— What is Tom like? — He is polite and _______ to the old.
. .---Who ________ it be that is knocking at the door? ---It________ be Mother, but I’m not sure.
. .If you cheat in the exam, you could hardly________ it.
. .He once studied in Zhejiang University, ________he went abroad for further study.
. .More attention should be paid __________ English.
. .More than 60 million people in southwestern China ________the drought nowadays as a result of less rainfall, environmental damage and so on