1.hypothesise 假设
I have long hypothesized a connection between these factors.
我一直以来就认为这些因素之间存在着某种关联 。
2.be vulnerable to 易受
Their tanks would be vulnerable to attack from the air
他们的坦克易受到空袭 。
3.bargaining chip 谈判的筹码
Rubio suggests that oil be used as a bargaining chip in any trade talks.
鲁比奥建议把石油当作所有贸易谈判的筹码 。
4.expire 期满;终止
His term of office expires at the end of June.
他的任期六月底届满 。