選A說明 prevent sb. from doing...這個短語妳了解，"阻止、禁止某人做某事"
shoot 是射擊的意思，at後面接射擊的目標，shoot at可以看成壹個固定搭配
22._In spite of_____the difficulties associated withthe project,we’ll go on with it.
given放在句首是考慮到...鑒於...的意思，in spite of 是雖然、盡管，不管
thanks to 幸虧，多謝 because of 因為，由於
go on with 繼續
盡管這個工程有很多困難，我們仍然堅持下去。
23.He shouted to them__at____the top of his voice but wasn’t heard.
他用最高音量向他們喊叫，但是他們沒聽到。at the top of his voice可以看成固定搭配
from 是“從,..”的意思，肯定是錯的啦
24.Will you come back to your hometown__on____Christmas?
這道題目我認為on 和 at 都可以，on Christmas: 壹般是 on Christmas Eve 就是在聖誕夜、平安夜，at Christmas是指在聖誕節那天
我認為選 at 其實更好，呵呵
25.Your suit won’t be ready__till___Friday.You can fetch it next Monday.
我認為這兩句話語境不夠好很容易選on，而且on也不能說百分百是錯的
till: 表示“直到。。。”前面壹般用否定。妳的西裝直到周五前都好不了，所以妳下周壹過來取吧。
如果選till 把句子改成這樣可能更好 Your suit ...till Friday. You can fetch it that day.
on：表示當天。妳的西裝周五那天好不了，所以妳下周壹過來取吧。
26.Although he was weak,__yet_____he tried his best to do the work.
Altough...yet....盡管...還是... 固定搭配，yet 也可以不要
盡管他很虛弱，但是他仍然盡力工作。
27.Some people love cats,_but_others hate them.
but表示強烈轉折，while "然而" 語氣沒有but這麽強烈
He is a teacher while I am a doctor.
這個需要多看句子去體會，參考這裏：/link?url=CSugsGejhKUQS8DSjGu8eZCps2FP86tHM15QR_6wx92v0nYokDNbRKtv0Njak8RoC0zf0QGPZiuqeJ9Z3xh5Wq
28.They were not the bones of an animal,__but____of a human being.
這些不是動物的骨頭，而是人類的。
實際上這是個省略句，補充完整妳就好理解了 They were not the bones of an animal, but the bones of a human being.
instead of: 代替，而不是
She went to the zoo instead of going to dance. 她去了動物園而不是去跳舞。
contrary壹般慣用的短語是on the contrary 相反地，壹般用在句首
to the contrary 壹般做後置定語. 這兩個短語區別和例句請參考：/question/174513957.html
contrary of這不是壹個短語，表示相反
The contrary of "hot" is "cold". 熱的對立面就是冷。