讲解：
exchange of sth
交换；互换；交流；掉换:
The exchange of prisoners took place this morning.
今天早上交换了俘虏。

score sth
(在物体表面)划下痕迹,刻出记号:
Score the card first with a knife.
先用刀在卡片上划出痕迹。

an watchful eye
注意的；警惕的；提防的:
His mother kept a watchful eye on him.
他的母亲特别留心他。

as / so long as
只要:
We'll go as long as the weather is good.
只要天气好我们就去。

be on track
步入正轨；做法对头:
Curtis is on track for the gold medal.
柯蒂斯正踏上夺取金牌之途。

intimidating (for / to sb)
吓人的；令人胆怯的:
This kind of questioning can be very intimidating to children.
这种问话的方式可能让孩子们非常害怕。