guarantee
vt.保证，担保 n.保证，保证书
The law guarantees equal rights for men and women.法律保证男女平等。
guard
n.警戒;看守，卫兵 vt.守卫 vi.防止，防范
There were two security guards on duty outside the building.大楼外面有两名安全警卫在值勤。
hitherto
ad.到目前为止，迄今
a species of fish hitherto unknown in the West迄今在西方还不为人知的一个鱼种
incentive
n.刺激，鼓励
As an added incentive , there’s a bottle of champagne for the best team.给最优秀的队发一瓶香槟作为额外的鼓励。
incline
v.(使)倾斜;倾向于，赞同 n.斜坡，斜面
The accident inclined him to reconsider his career.这次意外事件使他重新考虑起他的职业。
