分析句子中的非谓语动词?12句子中那个是非谓语动词
1.To learn English is not easy.
2.He found it very difficult to get to sleep..
3.Lucy asked me to turn down the radio..
4.His wish was to become a scientist.
5.There is nothing to worry about.
6.He woke up to find everybody gone..
7.Learning new words is very useful to me.
8.The music is exciting.
9.The boy singing now is a classmate of mine..
10.One day she came into my room laughing happily.
11.The other students in the class keep their eyes closed.
12.Built in 1949,the exhibition hall is almost 50 years old.