下列属于后天学习行为的是（　　）

根据句意及所给的汉语，补全所缺的单词，每空限填一词。
____ The girl often helps me with my __________（最糟糕的）subject.
____ I think you made a good _________（决定）.
____ We looked at each other in _________（沉默）.
____ I had an unusual           (经历) last Sunday.
____ You shouldn’t _________ (播放) your CDs too loudly.
____ Now many students are under too much __________（压力）.
____ If Paul _________（失败）the exam again, his teacher will talk with his parents about it.
____ He had an accident. But ___________（幸运地）, he was not badly hurt.
____ It is very __________（危险的）to play football in the street.
____ He didn’t know what was __________（发生）outside.