M01 laws tm4 5700. indd

B 1.  Hoping to save labor costs, automobile 
manufacturers want to replace assembly line 
workers with robots.
 2. 
Labor unions, fearing the loss of jobs for their 
members, are resisting the introduction of 
robots into factories. (Also possible without 
commas.)
 3. 
Union members, protesting the loss of jobs, 
went on strike.
EDITING PRACTICE 
(page 277)
One of the biggest problems facing humankind 
in the next few decades is the problem of global 
warming. In the past 150 years, global temperatures 
have risen approximately 1°C (1.8°F). The warmest 
year ever recorded occurred in this century. If 
temperatures continue to rise, the consequences 
could be catastrophic. As Earth’s temperature rises, 
polar ice will melt, causing the water level of the 
oceans to rise. Rising ocean levels, in turn, will 
cause flooding along the coasts. Global warming 
will also cause major changes in climate that will 
affect agriculture. For example, crops previously 
grown in Guatemala may not do so well because it 
will become too hot.
Believing that the increase in carbon dioxide in 
Earth’s atmosphere is the primary cause of global 
warming, scientists have urged action to decrease 
CO
2
levels. They are asking the world’s governments 
to sign an agreement controlling the amount of 
CO
2
released into the atmosphere. Thus far, not all 
governments have committed to doing so. After 
signing such an agreement, each government will 
have to enforce it. Individuals, corporations, and 
government officials will all have a responsibility to 
help keep our planet safe from harm.
APPENDIX C Punctuation Rules 
(pages 299–308)
PRACTICE 1: Using Commas 
(page 301)
x