1.sign up 签约

例句：He signed up as a flight attendant with Korean Air.
他与大韩航空公司签了约，当机乘员RDq3.^p^jc(Z%DA。

2.brood about 沉思

例句：As historians we brood about the study of the history.
作为历史学家，我们关心的是研究历史HSMgy+*;EVy2OEEl,^o,。

3.as well as 不但…而且

例句：She can play tennis as well as basketball.
她也会打篮球，也会打网球N%)~TPLc7KUZc[e7Y。

4.be used to 习惯于

例句：This piece of cloth can be used to make a pair of pillow cases.
这块布可以做一对枕套LAJM558q4_O。