下周就考了，求教prep 172 (sc-1 20)

172. The hognose snake puts on an impressive bluff, hissing and rearing back, broadens the flesh behind its head the way a cobra does, feigning repeated strikes, but, having no dangerous fangs and no venom, eventually, if its pursuer is not cowed by the performance, will fall over and play dead.

A. broadens the flesh behind its head the way a cobra does, feigning repeated strikes, but, having no dangerous fangs and no venom,

B. broadens the flesh behind its head the way a cobra does and feigns repeated strikes, but with no dangerous fangs and no venom,

C. broadening the flesh behind its head the way a cobra does and feigning repeated strikes, but it has no dangerous fangs and no venom, and

D. broadening the flesh behind its head the way a cobra does and feigns repeated strikes, but with no dangerous fangs and no venom, and

E. broadening the flesh behind its head the way a cobra does, feigning repeated strikes, but with no dangerous fangs and no venom, and

A: 两个动词之间应该有连词

B: 同上

C: correct

D: broadening 和 feigns不平行；but with no 不如用句子表达好

E: broadening 和feigning之间必须有连词

问题，B，C， B结构，snake do， do， but will do为什么不对？

C中间，snake do，doing and doing, doing, but it do, and will do 前面3个doing是不是有混淆的可能，而且应该是doing，doing and doing

我是这样想的，

平行结构--〉排除A,D,E

B与C比较

1.结构上，

B：snake do 1', doing 1 and doing 2, do 2' and do 3', but with phrase, if its pursuer,...will do

C: snake do（do代does了）, doing 1 and doing 2, doing 3 and doing 4, but it do... , if its pursuer，...will do

with phrase 修饰对象不明确

2.句子意思上，

snake puts on an impressive bluff, hissing and rearing back，broadening the flesh behind its head the way a cobra does and feigning repeated strikes

后面的doing1 and doing2,doing3 and doing4都是对puts on an impressive bluff的解释说明，描述snake这一系列动作-->puts on an impressive bluff.

but后面的it 补出也使得后面if...,...结构中的主语省略合理化一些。

哪位NN帮忙解释一下这句话什么意思？看不懂啊