Câu hỏi: I would like to send these letters …………………..air mail.

A. in

B. with

C. by

D. over

Câu 1: The two children blamed each other ...... the window.

A. to break

B. breaking

C. for breaking

D. having broken

Câu 2: The leopard is _________ the threat of extinction.

A. in

B. on

C. under

D. below

Câu 3: The panda's ...... habitat is the bamboo forest.

A. nature

B. natural

C. naturalized

D. naturally

Câu 4: A hydroelectric dam ______________ in this area now.

A. is building

B. is being built

C. build

D. was built

Câu 5: The ...... friendly products are designed not to harm the natural environment.

A. environment

B. environmental

C. environmentally

D. environmentalism

Câu 6: The film _______ by the time we ________ to the cinema.

A. already began - got

B. have already begun - got

C. had already begun - got

D. already began - had got