At the time when technology means ever more harmful carbon in the air we breathe, we need these forests now more than ever.（英译中)

When current and voltage reach maximum values at the same time, the power factor is .A.min

Tell me the exact time when the next plain will leave.A.awareB.accurateC.actualD.abroad

At a time when the world is short of causes for celebration, here is a candidate: within t

I __________ along the street when he shouted at me.A. walkedB. was walkingC. walk

A potato farmer was sent to prison just at the time when he______have been digging the gro

He told me that the number of students to be admitted at that time.A. had not been dec