227- The distance between Mars and the Sun changes due to ................ .
A) the big eccentricity of the former's oval-shaped appearance
B) the latter's irregular shape
C) the fact that there are atmospheric conditions in space
D) the fact that the former completes its tour around
the latter much later than the Earth
E) the undetectable rays emerging from the other planets between them
228- "24 hours and 37 minutes" is mentioned in the passage to signify ............... .
A) the length of time of one tour of the Earth around
Mars
B) the distance between Mars and the Sun from the point of time
C) the span of one tour of Mars around itself
D) the similarity between Mars and the Earth
E) the duration when Mars can be best observed in a year