All the students find ____ interesting and useful to speak English.

The PLA soldiers came to the ruins of Yushu and after ______ seemed to be a long time, they helped some victims out.

Have you heard that the research he spent most of his time_______ perfect success

Susan, why are you still here They are all ready to start.—I’m sorry, but I _________ when to start.

The training equips the students with ______ full understanding of first aid, which can make ______ real difference.