usedto be

过去是

have to be───必定是，无疑是

to be───存在

used to───惯于；过去经常

used up───用完了的；筋疲力尽；被杀死的

put to bed───安顿…去睡

user's fee───用户费用

information service is a kind of important work at a library, it should be usedto serve teaching and scientific research at prefectural and municipal Party school libraries.───信息服务工作是图书馆的一项重要工作，地市党校图书馆应利用信息服务更好地为教学和科研服务。

is a very largeblock of ice to all of a sudden be in a path a penguin might be [usedto] taking, " she said.───她说：“这座非常巨大的冰山，可能会突然阻挡在企鹅惯常经过的道路上。”