阅读下面短文, 在空白处填入1个适当的单词或括号内单词的正确形式。

Different kinds of birds build different kinds of nests. Birds build nests in all sorts of places, from on the ground to high up in trees and on the sides of mountains. Some birds make nests 【小题1】 float on water in wet areas. The materials birds use to build nests depend on the 【小题2】 (surround) area.

The reason birds make nests is to have a 【小题3】 (protect) place to lay their eggs in and take care of young birds after they hatch. When building a nest, birds try not to be seen. They do not want 【小题4】 (danger) animals to see 【小题5】 their eggs are. However, if you watch 【小题6】 (close), you may be able to see birds carrying 【小题7】 (branch) and other things to build their nests with.

Most birds nest during the spring and early summer of each year. They raise their babies in quite a short time. They lay the eggs, and then keep them warm for three to four weeks. After they hatch, many young birds learn to fly in 【小题8】 little as ten days. Some birds return to the same nest year after year if they 【小题9】 (raise) their young successfully in it before. Often, there are old and new nests in the same tree. This 【小题10】 (confuse) animals which are looking for baby birds to eat.