The time and effort he has devoted during the past few years _____ trees in that village are now considered to be very important.

The microphone _______ them to keep in touch; in other words, it made it possible for them to contact each other.

Too much drinking will do________to your health；you should take the doctor’s advice.

In order to make students have a good knowledge of science subjects, they are encouraged to______ their own science experiments.

---I think he is taking an active part in social work.  ----I agree with you ________.