1.  The Wallerstein study indicates that even after a decade young men and women still experience some of the effects of a divorce occurring when a child.

(A)  occurring when a child

(B)  occurring when children

(C)  that occurred when a child

(D)  that occurred when they were children

(E)   that has occurred as each was a child

og解释Choice E includes an incorrect verb tense (has occurred) and wrongly replaces when with as.

我的问题，as 和when 到底有什么区别啊？我看不明白og提问总结里的解释，那里只说明as when的用法，但是，as 和when 到底有什么区别我还是不清楚啊。

4. The only way for growers to salvage frozen citrus is to process them quickly into juice concentrate before they rot when warmer weather returns.

(A)   to process them quickly into juice concentrate before they rot when warmer weather returns

(B)   if they are quickly processed into juice concen­trate before warmer weather returns to rot them

(C)   for them to be processed quickly into juice concentrate before the fruit rots when warmer weather returns

(D)   if the fruit is quickly processed into juice concen­trate before they rot when warmer weather returns

(E)    to have it quickly processed into juice concentrate before warmer weather returns and rots the fruit

og解释Choice A begins with an infinitive, but the plural pronouns them and they do not agree with the singular noun citrus.

我的问题 在韦伯字典上citrus可以单复数相通的，为什么这里一定是单数呢

请求大家帮助。先谢谢大家了。

when 从句表示的时间是一具体的时间是a brief,finite moment,
as 表示的是an extended period of time。

while表示两个动作同时进行

as: two situations which develop or change together.

As I get older, I get more optimistic.

while: two actions happen at the same time.

while you are reading the information, I am working.

when: refer to ages and periods of time.

when I was a child, we in in london.

2。按照意思，应该是属于一个集体名词形式。。。有些随便说了，大家讨论吧

谢谢大家，我慢慢消化，人老了，反映能力下降了，呵呵。

“按照意思，应该是属于一个集体名词形式。。。”

我也觉得是集体名词，如果是集体名词的话，就可以用单数代词指代了吗？

less是可以作名词

less
n.
1、A smaller amount:
2、较小数：
She received less than she asked for.
她得到的比她要求的少
3、Something not as important as something else:
4、较次要的东西：
People have been punished for less.
人们因小事而受到惩罚

摘自美国传统词典（双解），其实就是金山词霸上的，

不客气，我也是大菜鸟，终于开始学着翻字典了。：）

"og上面说to do是名词decision的equivalent......"什么意思？

再问第4题？？？？自己顶一下。

“按照意思，应该是属于一个集体名词形式。。。”

我也觉得是集体名词，如果是集体名词的话，就可以用单数代词指代了吗？

意思是the decision ...is whether to sign;

           whether to sign=decision