各位老师们，红线标注的 the extent to which 为什么要有这个 to, extent后面不是一个which引导的限制性定语从句直接修饰extent 吗？为什么要有to 呢？我知道有一个短语是to the extent, 但是不明白这个句子为什么要有to. the extent to which…...
If only I were a poet so that,with all the sweet and beautiful words at
my command,I could sing of the grandeur of Peiping
in as longing a note as that of a cuckoo!
...红花绿叶，使我惊讶而欢喜！Returned from the bitter cold North with its drab and dried up vegetation, I was amazed and delighted when greeted by the charming scenery of sapphire mountains and emerald rivers as well as red flowers and green leaves.
Rather than asking for 300 hours’ practice to qualify to wash hair, for instance, the state of Tennessee should let hairdressers decide for themselves who is the best person to hire. 在to qualify to wash hair中，to wash hair是qualify的定语，to qualify是表目的。...
A
lot of work to be done, he had to go to the office quite early.A
lot of work to do, he had to go to the office quite early.这两句话哪个对，哪个错？错在哪了，请详细说明。之前的解答有的没看懂。
比如 incentive，这个单词，牛津词典上给的是 ~to sth / to do sth，为什么他能跟介词to同样能跟不定式 to do呢；再比如 prone 这个单词，牛津词典上给的同样也是 ~to sth / to do sth。For all her experience, she was still ...
It is important for the government to tighten regulation on some behaviour,especially those which have been proven to be damaging to health.句中为什么用to be damaging to health这种形式?damaging是形容词吗？
...拟语气）I’m really very busy, otherwise I would certainly go there with you. 我真是非常忙，否则我一定会和你一起去那儿的。（用了虚拟语气）
We didn’t know his telephone number; otherwise we would have telephoned him. 我们不知道他的电话号码...