Dressed untidily and speaking in a strange way, Father must have ______ to the people present to be a silly old man.  

Pleasant music is often played       classes to make students refreshed and relaxed for a while.

Don’t forget to bring a dictionary next class. ___. I didn’t catch what you said.

--- The patient looks much better.    is it that has made him      he is today?--- Perhaps the special medicine and his family’s patient care.  

The main cause of HIV / AIDS infection in China is drug abuse,  ______ is very serious in Yunnan.