Cambridge ielts 1-15 series reading answers explained

CAMBRIDGE IELTS 8 – TEST 4 – PASSAGE 1
LAND OF THE RISING SUN 

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BIOLOGICAL CONTROL OF PESTS 
QUESTIONS 14 – 17 CHOOSE THE CORRECT LETTER, A,B,C OR D 
14. THE USE OF PESTICIDES HAS CONTRIBUTED TO 
In paragraph 1: “Apart from engendering widespread ecological disorders, pesticides have 
contributed to the emergence of a new breed of chemical-resistant, highly lethal 
superbugs”. 
This means that the use of pesticides is partly responsible for widespread ecological disorders 
and the development of highly lethal superbugs ~ types of insects that are very difficult to destroy and 
which cause a lot of damage. This results in an imbalance in many ecologies around the world. 
– around the world = widespread 
– imbalance = disorders 
=> ANSWER: B – an imbalance in many ecologies around the world. 

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15. THE FOOD AND AGRICULTURE ORGANIZATION HAS COUNTED 
MORE THAN 300 AGRICULTURAL PESTS WHICH 
In paragraph 2: “more than 300 species of agricultural pests have developed resistance to a wide range 
of potent chemicals”. That means pesticides no longer affect/ have any effect on these agricultural 
pests. 
– no longer responding to = have developed resistance to 
– pesticides = potent chemicals 
=>ANSWER: A – are no longer responding to most pesticides in use. 
16. COTTON FARMERS IN CENTRAL AMERICA BEGAN TO USE 
PESTICIDES 
Paragraph 4 refers to cotton farmers in Central America: “farmers avidly took to 
pesticides as a sure measure to boost crop yield”. That means farmers used pesticides to 
increase the amount of cotton harvested from each crop ~ the crop yield. 
– began to use = took to 
– boost: to make something increase 
=>ANSWER: D – to ensure more cotton was harvested from each crop 
17. BY THE MID-1960S, COTTON FARMERS IN CENTRAL AMERICA 
FOUND THAT PESTICIDES 
In paragraph 5: “By the mid-1960s, the situation took an alarming turn with the outbreak of four more 
new pests, necessitating pesticides spraying to such an extent that 50% of the financial outlay on 
cotton production was accounted for by pesticides”. 
This means that pesticides accounted for 50% of the amount of money spent on cotton 
production. 
– financial outlay: the money that you have to spend in order to produce cotton 
=>ANSWER: D – were costing 50% of the total amount they spent on their crops 
QUESTIONS 18 – 21 
18. DISEASE -SPREADING PESTS RESPOND MORE QUICKLY TO 
PESTICIDES THAN AGRICULTURAL PESTS DO. 
Key words: disease-spreading pests, respond, more quickly, pesticides, agricultural pests. 
In paragraph 2, the FAO states that “more than 300 species of agricultural pests have 
developed resistance to a wide range of potent chemicals. Not to be left behind are the 
disease-spreading pests, about 100 species of which have become immune to a variety of insecticides 
now in use”. In this paragraph, the writer only refers to the number of species 
of both agricultural and disease – spreading pests which respond to pesticides. There is no mention 
of which type of pests develop resistance to pesticides more quickly. The information is not given. 
– respond to = develop resistance to 
– respond to = become immune to 
=> ANSWER: NOT GIVEN 
19. A NUMBER OF PESTS ARE NOW BORN WITH AN INNATE 
IMMUNITY TO SOME PESTICIDES 

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Key words: pests, born, innate immunity, pesticides 
In paragraph 3: “Because of their tremendous breeding potential and genetic diversity, many 
pests are known to withstand synthetic chemicals and bear offspring with a built-in 
resistance to pesticides”. That means these species are born with an innate immunity/ to 
insecticides. 
– born with ~ some pests give birth to young/offspring which are not killed by chemical pesticides 
– withstand ~ resist/be immune to/not be killed by 
– insecticides ~ chemicals/pesticides which kill insects innate: that you have when you were born 
=>ANSWER: YES 
20. BIOLOGICAL CONTROL ENTAILS USING SYNTHETIC CHEMICALS 
TO TRY AND CHANGE THE GENETIC MAKE-UP OF THE PESTS‟ 
OFFSPRING. 
Key words: biological control, synthetic chemicals, change, genetic make-up, pests‟ offspring. 
In paragraph 7, “In the face of the escalating perils from indiscriminate applications of pesticides, a 
more effective and ecologically sound strategy of biological control, involving the selective use 
of natural enemies of the pest population, is fast gaining popularity – though, as yet, it is a new field 
with limited potential”. 
The writer states that „biological control‟ is a more effective and ecologically sound 
strategy, used in an effort to tackle the serious danger caused by the application of 
pesticides. This means that „biological control‟ does not use pesticides but uses natural 
enemies of pests. => It is false to say that “Biological control entails using synthetic chemicals 
to try and change the genetic make-up of the pests‟ offspring”. 
– peril: serious danger 
– indiscriminate: action that is taken without thought about what the result may be, especially 
when it causes people to be harmed 
=>ANSWER: NO 
21. BIO-CONTROL IS FREE FROM DANGER UNDER CERTAIN 
CIRCUMSTANCES 
Key words: bio – control, free from, danger, circumstances 
In paragraph 7, the writer mentions “the advantage of biological control in contrast to 
other methods is that it provides a relatively low – cost, perpetual control system with a 
minimum of detrimental side – effects. When handled by experts, bio – control is safe, non – polluting 
and self – dispersing”. 
– Under certain circumstances [when handled by experts], bio-control is safe, non-polluting and self-
dispersing = free from danger. 
=>ANSWER: YES 
QUESTIONS 22 – 26 
22. DISAPENE SCALE INSECTS FEED ON 
The last sentence in paragraph 9 explains that “CIBC is also perfecting the technique for breeding 
parasites that prey on „disapene scale‟ insects – notorious defoliants of fruit trees in the US and India” 
=> This means that disapene scale insects feed on fruit trees. 
– notorious: well known for being bad 
– defoliant: these insects eat the leaves from plants, in particular the leaves of fruit trees 
=>ANSWER: D – Fruit trees 

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23. NEODUMETIA SANGAWANI ATE 
In paragraph 10: “Neodumetia sangawani, was found useful in controlling the Rhodes grass-
scale insect that was devouring forage grass in many parts of the 
US”. This means Neodumetia sangawaniate ate Rhodes grass-scale insect to control it from 
devouring [eating] forage grass. To be clear, Neodumetia sangawani eats grass-scale insects, and 
grass-scale insects eat forage grass. 
– ate = was devouring 
=>ANSWER: H – Grass-scale insects 
24. LEAF-MINING HISPIDES BLIGHTED 
In paragraph 10: “In the late 1960s, when Sri Lanka‟s flourishing coconut groves were 
plagued by leaf-mining hispides, a larval parasite imported from Singapore brought the pest 
under control”. This means that Sri Lanka‟s coconut groves were damaged by leaf-mining hispides. 
– blight = plague 
– flourishing: developing quickly and being very successful/productive 
grove: a small group of trees 
=> ANSWER: C – Coconut trees 
25. AN ARGENTINIAN WEEVIL MAY BE SUCCESSFUL IN WIPING OUT 
In paragraph 9, “Similarly the Hyderabad – based Regional Laboratory (RRL), supported by CIBC, 
is now trying out an Argentina weevil for the eradication of water 
hyacinth”. That means an Argentinian weevil may be successful in destroying all of the water 
hyacinth plants [by eating them] 
– hyacinth: a plant with a mass of small blue, white or pink flowers with a sweet smell that grow 
closely together around a thick stem 
– wiping out = eradication 
26. SALVINIA MOLESTA PLAGUES 
In paragraph 10: “By using Neochetina bruci, a beetle native to Brazil, scientists at Kerala 
Agricultural University freed a 12-kilometer-long canal from the clutches of the weed Salvinia 
molesta…About 30,000 hectares of rice fields in Kerala are infested by this weed [Salvinia molesta]”. 
That means weed Salvinia molesta plagues about 30,000 hectares of rice fields in Kerala. 
– plague = infest 
=>ANSWER: B – Rice fields