15. B。“It be + 形+for sb. + to
do” 表示对某人来说做某事怎样(简单、困难、重要……)而of sb.表示人的性格或品质，如kind, bad,
nice 等。
A thirsty bee went to a river to drink. As it was drinking,
the bee was 1 away by the running water.
A kind bird saw that the bee was in 2 .
It picked 3 off a tree and threw
4 into the water in front of the bee. The bee climbed
5 the leaf, and it was brought 6 to the
land. The bee thanked the bee a lot and then 7 .
Not 8 that, the bird was
sitting 9 the branch of a tree. It did not know that a
man was shooting at it. But the bee saw 10 the man was
doing. So it flew into the man’s 11 and stung(刺蜇) him. The 12 in the man’s eye was so great
that he was not able to 13 the bird, and the bird flew
away.
14 the bee, 15 life had
been saved by the bird, was able to save the life of the bird.