55. The problem for me was that there were no symptoms; it seemed to have sneaked up on me.

点睛　

sneak up为美国俚语，意为“悄悄爬上来；鬼鬼祟祟地行事”。如：
Don't sneak up behind; you scared me. 不要突然在我后面出现，你吓坏我了。
在口语中，俚语是很常见的，但是俚语又是很多考生的弱项，这就要求考生在平时的学习中注意收集一些常用俚语。

考点归纳　

比较常见的俚语有：
go up in smoke意为“成为泡影”。如：
Peter's vacation plans went up in smoke when a crisis arose in the office. 办公室里出了问题，彼得的假期泡汤了。
come again意为“再说一遍”。如：
Come again? I didn't quite understand what you said. 再说一遍好吗？你刚才说的话我不太明白。
spill the beans意为“泄露秘密”。如：
Don't spill the beans. It's supposed to be a secret. 别说漏了嘴，这可是个秘密哦！
in hot water意为“有麻烦”。如：
He is in hot water with his girlfriend recently. 最近他跟女友的关系有点僵。
go with the flow意为“随从大家的意见”。如：
Sharon is an easy-going person. She always goes with the flow. 莎伦是个随和的人。她总是听大家的意见。
get the ball rolling意为“开始”。如：
Let's get the ball rolling. 我们开始吧。
get one's feet wet意为“参与；开始做”。如：
It's not good to concentrate all your efforts on just writing. You should get your feet wet and try painting or dancing. 光把时间用在写作上对你不好。你应该尝试一下绘画或舞蹈。