Words _____ me when I wanted to express my thanks to him for having saved my son from the burning house.

Mr. Wang _______drive to work, but now he _______there by bike to keep healthy.

Though most people know that smoking __________ the risk of cancer, it is still hard for them to give it up. [ ]

We were required not to ______ any important details before they were made public.

If I ＿＿you . I＿＿study harder.