Recently, however, scientists have been finding that long-term use of these fertilizers can cause damage to the land, thus _____it less fertile.
.The Red Army ____ more than 25,000 li and arrived at North Shanxi at last.
News reports say peace talks between the two countries _____ with no agreement reached.
---What made you so angry?
I went to bed early _____ the sleep lost last night.
After the bell rings, which indicates the ending of the exam, you_____ stay ____ you are until all your papers are collected.