The terrible accident is under investigation.— Actually, quicker action ____ those workers trapped in the mine. [ ]

What do you think of the book I lent you yesterday?-Oh，not too bad.It’s not too difficult________.[ ]

Have you heard of Earth Day —-Yes . The first Earth Day ______ in 1970 toeducate us to protect our planet .

Peter took advantage________ his visit to Paris to improve his French

een, for _____ life had been very hard, donatedhis possessions to earthquake-hit families in Sichuan.