请教： Princeton 模考中一道语法题（每人能解释一下吗?)

A grasshopper is larger than normal for a member of the insect class; its obdomen can be up to two inches in length, as opposed to the one inch-long abodmen of the average insect.

A. normal

B. is normal

答案是B, 不明白呀。。。

here is what i think: you can either say

1.A grasshopper is larger than what is normal for a member of the insect class

or

2. A grasshopper is larger than normal member of the insect class

i guess you can rid of "what" in scenario 1.

我猜是这样

A grasshopper is larger than （a grasshopper） is normal for a member of the insect class; its obdomen can be up to two inches in length, as opposed to the one inch-long abodmen of the average insect.

作为昆虫的一员，与其说草蜢身材标准，不如说算是较大一号的。

请NN指正。

如果是larger than normal会产生一种可能的歧义,就是将larger和normal两个形容词比,似乎有了xxx is more intelligent than serious.的效果

如果改成larger than is normal,这种歧义就有效地避免了

个人之见,请大家指教

多谢楼上各位啦！