几道高中英语题,求详细解释

一开始看见有许多个回答,以为没我可做的事,但把各个回答看完,发现都不是完全正确,所以我也来凑个热闹,说说我的答案.
①Dr.Zhong was chosen to _____our hospital at the international meeting
A.represent B.stand for C.instead of D.take the place of
选A 正确.represent “代表一群人并为他们的利益说话”.stand for 指“缩写或符号代表某个意思”.instead of “代替”,是介词短语.take the place of “取代”.
②There is nothing unusual.All _____ going well.
A.has B.is C.have D.are
选 B 正确.这里 all 指“一切事情”,作为单数对待.如果 all 表示“所有的人”,则是复数含义.
③He _____ the story to be false.Which of the following is WRONG?
A.declared B.regarded C.considered D.believed
选 B 正确.这一题是找出错误的选项.declare sb./sth.to be + adj./n.“宣称某人或某物是……”,consider sb./sth.to be + adj./n.“认为某人或某物是……”,believe sb./sth.to be + adj./n.“认为某人或某物是……”,regard sb./sth.as …“认为某人或某物是……”.这几个词只有 regard 后面不能接 to be 作宾补.
④Many people agree that ______ knowledge of English is a must in _____ international trade
A.a; / B.the; an C.the; the D./; the
选A 正确.a knowledge of “精通”,trade“商业,贸易”,是不可数名词.
⑤At the beginning of class,the noise of desks ____ could be heard outside the classroom.
A.opened and closed B.to be opened and closed
C.being opened and closed D.to open and close
选C正确,指“课桌正在被打开和关上时所发出的声音”,这句话在十几年前的人教社统编教材高二英语课本中 The Last Lesson（最后一课）原文中出现.
⑥Having _____ no-meat day would be a good way of encouraging ______ low-carbon lifestyle.
A.a; the B.a；a C.the; the D.the; a
选 A 正确.a no-meat day 表示“具有某种特点的一天（或一个上午下午等）”用不定冠词,the low-carbon lifestyle 特指“低碳生活方式”.
⑦—Will you go to the party tomorrow,Lily?
—No,____ I was invited to.
此题选项没给出.个人认为用 though /although 表示让步比较合适,如果用 unless,则后面要用现在时态,如说成 unless I am/have been invited to.
⑧With all the problems ______,the manager left for home,_____.
A.solved; satisfied B.to be solved; with satisfaction
C.being solved; satisfied D.Having been solved; with satisfaction
选 A 正确.with all the problems solved “所有的问题都已经被解决”.B 选项中不定式to be solved 在时间上指将来,“所有的问题将要被解决”,还没有被解决,经理怎么会满意呢?C.being solved “正在被解决”,都不恰当.D 选项放在 with sth.结构中是错误的用法.如果把D 放入后面一句,说成 Having been solved,the manager left for home,satisfied.则 the manager 是 having been solved 的逻辑主语,“经理被解决了,经理满意地回家去.”意思是荒谬的.所以第一空一定要用过去分词 solved 作宾补.
第二空 satisfied 用过去分词,作伴随状语,说明经理回家去时的心情,这里用过去分词,其用法可以从固定词组 be satisfied with sth.找到原型.你的答案很正确，我还有几个问题希望你能尽快回答④中trade难道不能是特指吗？⑧中最后一空为什么可以只有1个过去分词？难道真的是satisfied放在逗号后面作主语补足语 with satisfaction不需要加逗号 吗？这是怎么回事？还有⑦也请你尽快回答4. trade 这里并没有特指某一次贸易或某种特殊的贸易，我把我手头的《牛津高阶英汉双解词典（第6版）》对该词的解释摘录给你看：trade, noun 1 [u] the activity of buying and selling or of exchanging goods or services between people or countries 贸易；买卖；商业；交易： ·international/foreign trade 国际/对外贸易 Trade between the two countries has icreased.两国之间的贸易增长了。the international trade in oil 国际石油贸易 the arms trade 军火贸易7. ⑦—Will you go to the party tomorrow,Lily? —No, ____ I was invited to. 第7题选项为 A.as long as B.so far C.as ifD.even if先看各选项的含义。A. as long as 只要；B. so far 到现在为止，到目前为止，常与现在完成时连用；C. as if 似乎，好像；D. even if 即使（假设兼让步），虽然。从意思上看，用排除法，A, B, C 均错误，只有 D. 选项意思勉强可以，所以该题答案选 D.但是，我还要表达个人看法，even if 后面的从句一般用现在时态，可以指现在或将来，而此题用了一般过去时，不是很好，如果改为 although, though, even though 就更好。从 even if的中文解释是看不出所适合的时态的。8. 最后一空的 satisfied 是过去分词作状语，我们一般不把它分析成主语补足语，也许外国人有这种说法。过去分词经常用逗号与主句隔开，作状语。如果用 with satisfaction，则空格前不能用逗号，而是与主句紧跟在一起。如果要再问为什么这样用，恐怕我只能说语言是约定俗成的，因为它就是这样使用的。