Câu hỏi: Ecologists are trying to preserve our environment for future generations by protecting the ozone layer, purifying the air, and have planted the trees that have been cut down.

A. to preserve

B. for

C. the ozone layer

D. have planted

Câu 1: Robots in the home might not be enough creative to do the cooking, plan the meal and so on.

A. in the home

B. might

C. enough creative

D. do the cooking

Câu 2: Thanks for the liberation of women, women can now take part in social activities.

A. thanks for

B. liberation of

C. can

D. take part in

Câu 3: Slowly and with care, the museum director removed the Ming vase from the shelf and placed it on the display pedestal.

A. with care

B. from

C. placed

D. the display pedestal

Câu 4: Unless there had been a heavy storm, the climbers will not have died.

A. Unless

B. had been

C. heavy

D. will

Câu 5: Abraham Lincoln was a good president and was self-educated, hard working and always told the truth.

A. a good president

B. self-educated

C. hard working

D. always told the truth

Câu 6: Jason’s professor had him to rewrite his thesis many times before allowing him to hand it in.

A. had

B. to rewrite

C. many times

D. allowing