根据括号中所给的汉语写出单词，使句子意思完整正确。

小题1:The       (架子) in the library are full of different kinds of books.

小题2:The train was very        (拥挤的), and I had to stand all the way.

小题3:This morning a bus hit a car near our school.        (幸运地), no one was hurt in the accident.

小题4:Tomorrow is my father’s        (第四十) birthday and I will buy a gift for him.

小题5:The radio says some wild wolves have to        (袭击) villagers because of the loss of living areas.

接触器的电磁机构由（）、（）和（）三部分组成。