回答：
A.Only seven people this century have been killed by the great white shark, the man-eater of the ------ killed by bee stings.
(1) 在分析多项选择答案1--5之前,最好先将原句的后半部分分析一下：the man-eater of the -----killed by bee stings. -----the man-eater of the movies 是同位语,补充说明其前的先行词（名词shark）；而其后的部分(5个答案) 是一非限定性定语从句,用来附加说明先行词shark的.弄清楚这一点,对理解下面的选择答案是非常有帮助的.
1 the man-eater of the movies—less than those killed by bee stings.
less一般是不用于修饰可数名词（此处指people）的,因此1.非最佳答案
2 the man-eater of the movies—fewer than have been killed by bee stings.
fewer than have been killed by bee stings---fewer than 之后漏掉了宾语those 或the people--还少一个关系代词who==正确答案： fewer than those(the people) who have been killed by bee stings；因此2.也非最佳答案；
3 the man-eater of the movies, which is less than those killed by bee stings.
less一般是不用于修饰可数名词,与1.相同；因此3.非最佳答案；
4 the man-eater of the movies, a number lower than the people killed by bee stings.
a number lower 此处用于可数名词 '人'(指 people)之前是不正确的；因此4.非最佳答案；
5 the man-eater of the movies, fewer than the ones killed by bee stings.
fewer 一般用于修饰可数名词(指 people),其完整的答案为==which is fewer than the ones killied by bee stings；因此5. 是最佳答案.
但是,赵振才教授指出：要说明的是：该题的出题者的意图是:fewer 用在可数名词之前,而less仅用于不可数名词之前,但英语惯用法不像上面所说的那样简单,而呈现错综复杂的局面.英语语法专家R.Quirk等指出,“有一种倾向,将less(而不用fewer) 和least (而不用fewest)与可数名词连用.”他还指出：“传统的规定语法反对把less 和least 与复数名词连用.然而,它们在非正式英语中,却用得十分广泛.著名英语语法家Swan 也指出：“从理论上讲,fewer用在复数名词之前,而less用于不可数名词之前.但是在现代英语中,特别是在非正式语体中,许多人在复数名词之前也用less,而不用fewer.”如：Less people are going to university than usual.(CCEU) 据此,英语语法专家认为,在英语考试中应回避此类考题.（请参见赵振才教授：《英语常见问题解答大辞典》）
B. A new hair-growing drug is being sold for three times the price, per milligram, ------the drug’s maker charges for another product with the same active ingredient. 前面句子的意思：“一种新型的增发剂以每毫克价格的3倍正在销售”
句子的后半部分是一非限定性定语从句,用来对前半句进行附加说明的；既然是定语从句,句子中就必须要有引导定语从句的关系代词（或关系副词）,1. as 2. than,都不能作关系代词,所以排除其为正确答案；4. of what : what 也不能作关系代词,不能引导定语从句,所以为非正确答案；5. at which：which虽是关系代词,但at which 用在该定语从句中语法是错误的,因此也是非正确答案；3. that 是关系代词,用来引导定语从句,其意思是：制药商对另外一种含有同样活性成分的产品要价（每毫克价格的3倍）.
1. as the drug’s maker charges for another product with the same active ingredient.
2. than he drug’s maker charges for another product with the same active ingredient.
3. that the drug’s maker charges for another product with the same active ingredient.
4. of what the drug’s maker charges for another product with the same active ingredient.
5. at which the drug’s maker charges for another product with the same active ingredient.
说的有点多了,望能对你有助.
