求教高手NN们！！！

Ricky2835

In addition to having more protein -than wheat does, the protein in rice is higher quality than that in wheat, with more of the amino acids essential to the human diet.
A.the protein in rice is higher quality than that in
B.rice has protein of higher quality than that in
C.the protein in rice is higher in quality than it is in
D.rice protein is higher in quality than it is in
E.rice has a protein higher in quality than
此题我选E 答案为B  有点搞不清楚E为什么不可以 比较的对象也对称

Ricky2835

More than one hundred years ago, students of ornithology reported that hummingbirds can hover as insects flitting gracefully from one flower to another.
A.as insects flitting gracefully from one flower to another
B.like insects flitting gracefully from one flower to another
C.as insects do that flit gracefully from one flower to others
D.like insects do that flit gracefully from one flower to others
E.as do insects that flit gracefully from one flower to some other one
还有此题，答案是A 但是as结构后面不是跟主谓结构么 而且做比较的话 like不是更好 而as可以比较 但也可以解释成“作为。。。” 这里as不是有歧义么？请教高手