I can’t send an e-mail. Would you please teach me it

.It is _____that he has been addicted to thedrugs and has difficulty quitting it.

18——- Could you please tell me more about the city? ——- Sorry, I’m a newcomerI know nothing else ______ you know now

Have you read the poems ______ by Du Fu—Of course, many of them.

The Australian boy has a good __________ of Chinese and can express himself freely in it.