these two sources are considered green energy because they produce a lot of pollution when they are burned.

A. joblessness

B. the jobless

C. the joblessness

D. the jobs

A. would die

B. had died

C. died

D. dies

A. out

B. even though

C. so

D. furthermore

A. be driving

B. drive

C. driven

D. driving

A. There is so much traffic these days that it is more pleasant to walk than to drive.

B. The traffic is always so heavy that you'd better walk to work; it's quicker.

C. It is faster to walk than to drive in heavy traffic at certain times of the day.

D. During rush hours, walking gives me much more pleasure than driving in the heavy traffic.

A. I passed the exam because I worked harder than others.

B. As I did not work hard enough, I did not pass the exam.

C. Although I worked very hard, I did not pass the exam.

D. Jack has investigated for days, suspected to have stolen credit cards.