重点讲解：
1.as far as we know 据我们所知；正如我方所知
例句：And as far as we know, the rates they quote are among the most competitive in the line.
据我们所知，他们的价格是业内非常有竞争力的。

2.the key to ...的关键
例句：The key to our success in the fight was that we knew the enemy's attacking routes in advance.
战斗胜利的关键在于我们很早就获知了敌方的进攻路线。

3.just right 正好；刚刚好
例句：First, he said the flesh was just right, not too firm and not too soft.
肉刚刚好，既不太嫩又不太老。

4.pay it a visit 亲自拜访
例句：The only thing the road cares about is that you pay it a visit once in a while.
这条路唯一在乎的是，你时不时来光临一次。