Progress so far has been very good . _______ ,we are sure that the project will becompleted on time.

Fred is second to none in English in our class, but believe it or not, he _____ passed the last exam.

Five firemen ________ escaped death when a staircase collapsed beneath their feet. 

He began to take political science        only when he left school.

The traffic problems have severely affected economic development. ________, we must spare no efforts to solve them.