1.buy off 收买
The thief tried to buy off the policeman, but he didn't succeed.
这贼企图贿赂警察,但他未达到目的
2.hush up 掩盖,防止…张扬出去
They tried to hush up the matter they hijacked a lorry driver.
他们想尽各种方法掩盖他们曾抢劫过一名卡车司机的事实
3.impose … on … 施加……于……
Congress can impose strict conditions on the bank.
国会可能会迫使这家银行接受苛刻的条件
4.in force 生效
The rule has been in force since 1 May 2011.
该规定于2011年5月1日起实行