So difficult ____ it to work out the problem that I decided to ask Tom for advice. [ ]

I really want to know the real reason for his being late.–His mother ______ you as soon as she ________ .

It was ______ we were returning home ______ I realized what a good feeling it was to have helped someone in trouble.

.He is________ to spend his special Children’s Day in Yunnan because of the earthquake..

Nanjing isn’t so large __________ Shanghai,however, it’s the second __________ city in East China.