1. invest vt.投资; 花费
例句:Can I be sure of a profit if I invest?
我要是投资, 肯定能获利吗?
2. communicate vt.传达,表达; 显示
例句:I communicate with him regularly by letter.
我们经常与他通信。
3. explain vt.讲解,解释
例句:Lastly I must explain that.
最后,我得解释一下那件事。
4. threaten vt.危及; 恐吓
例句:Black clouds threaten a storm.
乌云是暴风雨的先兆。