比较级类的题目请教

天山

请教一道语法：
A grasshopper is larger than   is normal   for a member of the insect class; Its abodomen can beup to 2 inches in the length, as opposed to the one inch long abodomen of the average insect.  
Confused choice: Normal   
不知哪个好？

joice

--- is larger than normal

7986

is normal 更合适些。
我考的时候碰到类似的题,也是问选 normal 还是 are normal。 不过句型是as...as， 道理是一样。than, as都可以看做代词作主语用，保留谓语。For examples:
1. Do not eat more than is good for you
2. It may be more important than would seem
英语中的习惯用法是more than usual, as usual. is normal 用在这里，语法应该没问题
在GMAT考试中than后面出现形容词似乎不多见, 就一些象than expected, than estimated之类而已. 倒是日常用的比较活，象Hongkong is drabber than drab, His hair was yet darker than it was grey. 当然这些不算

天山

分析得很好，严重感谢7986！

1stzhang

7986，我还是没有怎么看懂！Do not eat more than is good for you。在口语中十分常见，但是书面语好像并不多见。如果可以请你再分析一下？并分析一下句子的成分！

merlion

我的理解：（不肯定对，望指教）

"is larger than normal" 有点象"eat more than enough"

比较主语应在THAN后补足谓语以避免歧义或承接宾语， 有些除外(如that, those.., 通常不引起歧义.).
例如：
1。 Los Angeles has a higher number of family dwellings per capita than does any other large city. (XDF)
2。 Inflation has made many Americans reevaluate their assumptions about the future, they still expect to live better than their parents did, .... (XDF)
如不加谓语DID， 就成了 they still expect to live better (life) than their parents , 这样意思不通。
3。 if calves exercise and associate with other calves, they have require less medication and gain weight more quickly than those raised in confinement.

此处1）不象在比较主语，2） than normal 听起来意思表达正确。所以我选than normal

请明白人指教，谢谢

7986

greater than normal 意思好理解，实际写作也有这样用的，但语法说不过去。早年收罗了一台湾GMAT的讲义，是这么说的：
在情况相同但程度不同的比较句里面， than是主格，所以后面要接动词，这是GMAT修辞偶尔会考属于比较特殊的题型，注意到就可以了
1. This summer is warmer than is usual for the summer in Taipei
(今夏比台北惯常的夏季更热---情况相同但程度不同， 故than 是主格。这时， than it is usual 或 than as usual, than usual 都错，要消去）
2. The problem is more serious than was expected (也可省略为than expected)
此问题比彼时预估时更严重----情况相同但程度不同， 故than 是主格。

merlion

谢谢耐心指教， 不胜感激！

已经忘了语法的词汇，什么是“ than是主格”？... is warmer than (省了it 由than代？) is usual for the summer in T...

就这题而言，应是IS NORMAL FOR。 我忽视了NORMAL其后的FOR..., 把“LARGER THAN NORMAL”当成了形容词组（好象是可以用的）。如果把FOR及其后去掉， 是否可以用LARGER THAN NORMAL？ 望指教，谢谢了