When the teacher walked into the classroom,the students ____ at once.

下列各句中加横线词语的意义和用法不相同的一项是（ ）

下列各句中，没有语病的一句是（ ）

3—You had better not judge a person _______his appearance—I know all the people dressed _____rags are not beggars

__________ the directions exactly, you willnever get confused.