BBC news 2010-08-01 加文本

cut off切〔隔〕断, 阻碍

例句：Our troops cut off the enemy's retreat.
      我们的军队切断了敌人的退路。

2.The head of the UN's coordination office in Pakistan, Manuel Bessler, told the BBC he still could not describe with certainty the full scale of this emergency.

with certainty肯定地,确信地

例句：I can't say with any certainty about the company's future.
      我无法断言该公司的未来。

3.This time, the square in the city centre where the activists had planned to meet was sealed off so a group of rally-car drivers and quad-bikers could show off their skills.

show off炫耀, 卖弄

例句：He never shows off.
      他从不卖弄自己的才能。

      She likes to show herself off.
      她喜欢自我炫耀。

4. It's not immediately clear if this amounts to a complete restriction on how the peacekeepers are able to operate.

amount to意味着

例句：His words amounted to a threat.
      他的话实际上是威胁。