在下列各句的空白处填入一个最恰当的单词。
1.  Cao Chong had a good way to_____ the big heavy elephant.
2.  The room is too_____ for six persons to live in.
3.  Miss Li taught us a lot of useful _____ for example, agree in with other people.
4.  Manatees are very huge.  They are about l,000 _____. 
5.  In the zoo, animals have to live in small _____. 
6.  Parents should _____ their children to behave well.
7.  There isn't enough _____ left for the cows. They'll be hungry.
8.  He is _____. He always fights with others.
9.  _____ can't grow in the desert because there is no water there.
10.  My grandfather is about sixty years old and his hair has turned _____. 

用括号内所给词的正确形式填空。