重点讲解：
1. take sth. to the extreme 走极端；使…至极端；
Beauty, as the saying goes, is in the eye of the beholder--and some fish have taken this idea to the extreme.
常言道，情人眼里出西施——而有些鱼儿还把这种想法推到极致X[]7F.|34uTAcCrk!L。
2. fend off 挡开，避开(问题或人)；
He raised his hand to fend off the blow.
他抬起手来抵挡那一拳#*7Y0|V8u4。
3. get to the bottom of 找到…的真正起因；查寻到…的根源；
I have to get to the bottom of this mess.
我必须查清造成这一混乱局面的真正原因c~D4*,4#17eUHqc)。
4. in contrast 相比之下；与…相反；
In contrast, the lives of girls in well-to-do families were often very sheltered.
相反，生活在富裕家庭的女孩子通常都备受呵护-ASXoZCxVdE7g8j;。