16.The advertisements are trying ________ people to buy things they don‘t really need.

　　A. persuade

　　B. persuading

　　C. be persuading

　　D. to persuade

　　17.Practice ________ English every day.

　　A. speak

　　B. to speak

　　C. speaks

　　D. speaking

　　18.The discount houses were first established in that period of time ________ people‘s purchasing power was low.

　　A. which

　　B. that

　　C. when

　　D. where

　　19.Please write a report ________ the above subjects are to be covered.

　　A. which

　　B. in which

　　C. that

　　D. in that

　　20.The reason ________ I‘m writing is to ask for your permission to translate your latest novel into Chinese.

　　A. because

　　B. why

　　C. for

　　D. as