og 161 没人问过，那个虚拟语气

161. A wildlife expert predicts that the reintroduction of the caribou into northern Minnesota would fail if the density of the timber wolf population in that region is more numerous than one wolf for every 39 square miles.

(A)  would fail if the density of the timber wolf population in that region is more numerous than

(B)  would fail provided the density of the timber wolf population in that region is more than

(C)  should fail if the timber wolf density in that region was greater than

(D)  will fail if the density of the timber wolf population in that region is greater than

(E)   will fail if the timber wolf density in that region were more numerous than

我觉得if在这里表示一个condition，所以可以用虚拟语气，也就是would。

还是说if x happens, y will happen这个结构？

if条件什么时候用虚拟，什么时候不用阿？？？晕了

152. When the technique known as gene-splicing was invented in the early 1970's, it was feared that scien­tists might inadvertently create an "Andromeda strain," a microbe never before seen on Earth that might escape from the laboratory and it would kill vast numbers of humans who would have no natural defenses against it.

(A)  it would kill vast numbers of humans who would have no natural defenses against it

(B)   it might kill vast numbers of humans with no natural defenses against it

(C)  kill vast numbers of humans who would have no natural defenses against it(虚拟语气没有错)

(D)  kill vast numbers of humans who have no natu­ral defenses against them

(E)   kill vast numbers of humans with no natural defenses against them

In addition, choices B, D, and E lack would and thus do not express the conditional.

虚拟一般指不太有可能发生的事情,  如: If I were you, .....; 或者过去已成的事实, 而说的人好象吃了后悔药, 回到过去改变它. If I knew it, I should have.....

161表明一件事情发生的环境, 条件, 陈述了一个事实, 即在什么样的情况下reintroduction会失败.

谢谢小紫……可是，可是我觉得would的确是表达一种imagined situation啊，

请牛牛解答一下，如何区分if...will...和if...would……

from longman:

▶IMAGINED SITUATIONS◀

a) used when talking about a possible situation that you imagine or want to happen

What would you do if you won a million pounds?

I'd be amazed if I got the job.

I wish they'd come and visit us.

If only he would listen to me.

b) used when talking about something that did not happen, or a situation that cannot exist

Everything would be very different if your father were still alive.

I would have phoned you, but there wasn't time.

Alex would never have found out if you hadn't told him.

What would have happened if I hadn't been here?

imagined situation没错, 但并不是用了would, 再加上和后面的现在时不一致, 就一定是虚拟. would在这句句子应该属于上面的a, 表明一个事件的可能性, 译作"可能". 如果用will就会改变原文的意思, 变成"将要". 两个用法的语气是不一样的.

我也是这样觉得的……………………

可是这题正确答案就是D，要用will……

OG还专门说would错…………为什么不能用would？

tianwan大哥说，would书面语中一般不用

薄冰语法书上说：当should在主句中出现时，从句采用would，以避免重复

161.

the reintroduction of the caribou into northern Minnesota would fail if---：目前reintroduction没有fail；但是if---，reintroduction就会fail。

A wildlife expert predicts that the reintroduction of the caribou into northern Minnesota will fail if---：陈述将来的情况：（1）没有与现在事实相反的意思；（2）不是假设；所以不用虚拟。

我做题时根本就把选项D给排除了，认为句子是虚拟语气，必定是WOULD。

仔细体会一下MM的解释，的确，这里是在陈述一个条件，并指出“density”条件如果发生，那么“fail”的结果就会成立。