It is hard for us to eat better, exercise more, and sleep enough, ________ we know we should.
A. since B. even if
C. unless D. as if
At the conference, they came up with three different _____ to solving the serious problem.
A. approaches B. means
C. methods D. ways
The music brought the days back to me _____ I was out of work wandering hopelessly on the streets.
A. until B. that C. when D. which
Jack is the right person you can rely on to ____ the research when you are on vacation for the next two weeks.
A. carry on B. focus on
C. take up D. insist on
He failed the final examination and only then ____ how much time he had wasted.
A. he realized B. had he realized
C. he had realized D. did he realize
Recently, however, scientists have been finding that long-term use of these fertilizers can cause damage to the land, thus _____it less fertile.
A. make B. to make
C. made D. making
