Onethird of the area__________covered with green trees.About seventy percent of the trees__________been planted.
If only I _____ a few days ago!Then I wouldn’t have been feeling so worried now.
_____ money, the man was very rich, but he was not happy at all.
Though _____ of the danger, he still went skating on the thin ice.
In our school students are _____ according to how much they know and how old they are.
Make a tentative guess _____ Peking Man _____ have done and used thousands of years ago.