Lacking rain, many river in Yunnan province have______ recently.

To save the drowning child, the boy plunged into the icy water without hesitation, _____ his own safety[ ]

In the past two years, the number of campus bookstores offering rentals _____ from a few dozen to1,500.[ ]

Will you please try to ___ the article ___ to about 3000 words?

I have kept this letter from my class teacher _________I graduated 10 years ago.