－What were you doing when you heard Eastern Star went down in the river－I my homework.

I borrow a book from my friend and I can ________ itfor a week.

now, we have raised 50.000 pounds for the poor children, ______ is quite unexpected.

The plane finally landed and not a single passenger ______.

ationwide smog serves as a constant reminder, indicating that it’s high time we ______ on ourselves.