一篇英语语法填空，求解析原因

Question

　　Even for those who fail this year's exam, the education department in Qinghai will offer the students ___34___ (vary) opportunities to continue their education ___35___ receive vocational training, according to the ministry.
　　In China, the college entrance exam ___36___ (hold) in early June every year. About 1,000 students from Yushu's senior high schools are expected to sit this year's exam along with students from ___37___ the country.
　　___38___ 7.1 magnitude earthquake hit Yushu of Qinghai on April 14, killing at least 2,200 people and leaving some 13,000 ___39___ (injure).
　　On Saturday, Premier Wen Jiabao paid his second visit to Yushu ___40___ the quake and presided over a meeting on reconstruction work.

答案如下，
31. have been instructed 32. if/when 33. its 34. various 35. or 36. is held
37. across 38. A 39. injured 40. since

请解释为什麽填这些答案，尽量详细些，重在解释，谢谢！！！

Answer 1

various是不同的，各种各样的意思。这里需要形容词。
35）因为继续学习和接受职业训练不是先后顺序的或同时进行的，是两个选其一，所以用or,不用and
36）考试应该是“被举行”，此处被动
37）across the country意为横跨全国，固定搭配，from across也是。across the world/continent都是这种用法
38）主语earthquake可数名词，需要冠词。由于是在文中第一次出现所以用不定冠词a
39）有13.000人受伤了，就是“被伤害的”，可理解为形容词，leave...+adj.。也可以理解为过去分词，相当于“who were injured”
40)首先从“and”判断出句子有两个意思。quake之前是一个意思，那么此处应该填介词。由second得出此处填since，自从地震后的第二次慰问。

Answer 2

34.vary是动词，变化、改变。此处自然要用形容词修饰名称opportunities了，vary的形容词形式是various。
35.“continue their education ”和“receive vocational training”是两种不同的教育，所以用or。
36.考试被举行，用hold的被动形式，is held。
37.from across来自于……
例如：from across China"来自于中国各地"
38.一场地震，用冠词a。
39.形容词形式的词语有时可以代表一类人，injured=injured people
the wounded也是这样。
40.备选词是啥？我没法解释这道了。。。
（好几道你都没写备选词）本回答被网友采纳

Answer 3

34. various 后边的opportunities是复数，因此也用复数形式

35. or 这是选择性的，可以继续接受教育或者接受职业培训

36. is held 考试和举行之间是被动关系

37. across across the country固定搭配：全国各地

38. A 说是7.1级地震

39. injured leave + sb./sth. + 动词过去式 表示把某人或某事搁置在某个状态。

40. since （表示某情况自过去某时间点或某个事件以来一直持续到现在）自…以后，从…以来