问两题

1.all eels spawn in the sea,the eggs haching into transparent, ribbonlike larva ______, feeding until they metamorphose into small eels.

a.that drift about           b.drift about           c.about drifting        d.drift about them

答案是a，that是什么用阿？不明白，为什么不可以b

2.in western north America, _______ from the Great Divide which separates the areas from which waters flow either eastward to the Atlantic or westward to the Pacific.

a.the Rocky Mountains     b.where the  Rocky Mountains      

C.the Rocky Mountains in which       d.there are the Rocky Mountains

答案是a，为什么不能选d

3.although the huge ice masses ____ glaciers more slowly, they are a powerful erosive force in nature.

a.to call          b.calling        c.called

答案是c，为什么不选b       ，过去分词后不加名词，不是吗？

1，谓语spawn，ribbonlike larva that drift about 整体在句子只是个名词

2，空格后的from-form, 所以句子少主语

3，你题抄错了吧？

第3题是.although the huge ice masses ____ glaciers move slowly, they are a powerful erosive force in nature.

第二题的谓语是什么？flow？

还有一题 almost  every the hereditary material of an individual organism resides in the chromosomes.

答案是every变all，material是不可数？resides是跟an individual organism ?

到底every和all的用法区别在哪？

最后一题  in the United States, Maryland ranks second only to Virginia as a oyster-producing state.

答案是d，但我觉得b 都有错，second 应为 the second

3，although引导的状语从句move是谓语，空格called

=>ice masses which are called glaciers

2,谓语是form

every student,every three days（后加复数是每隔。。。的意思）,every now and then

all students,all day,all the morning,all+可数名词复数或不可数