My classmate always __________ a pen ____________me.

Is Doctor Green________ORBIS doctor—No， he is________UNICEF volunteer. But he sometimes works with ORBIS.

Have you read the book?—Yes. But that one is _____worth reading. I suggest you______ it if you have time.

Taking exercise__a good way__our body strong..

As nobody here knows what is wrong with the machine, we must send for an engineer to _________ the problem.