## 语法题目 ##
____ Eijah McCoy's invention of the lubricating cup in the early 1870's, machinery had to be stopped in order to be lubricated.
## 题目解析 ##
根据句意，想要表达的是「在……之前」，四个选项中只有 before 能够表达这个意思，所以选择 A 选项。这里需要注意，逗号前并不是一个完整的句子，所以 before 在这里是一个介词，而非连词。其余三个选项都是连词，要连接词与词或句与句。
## 知识点梳理 ##
常见介词：at, by, for, from, in, near, of, off, on, during, since, before, after, until; inside, out of, within, without, outside, throughout; as to, until after, except for; at the cost of, at the mercy of, by means of, in place of, by favor of, in spite of, in/with reference to, in/with regard with
① I have lived here <u>for a year</u>.
② I'll wait for you <u>till 10 o'clock</u>.
③ I <u>was familiar with</u> nobody <u>at the meeting</u>.
④ Swimming <u>is good for your health</u>.
⑤ We can see <u>with our eyes</u> and write <u>with our hands</u>.
⑥ We succeeded <u>by cooperating</u> <u>with them</u>.
⑦ She seems to know the solution <u>to the problem</u>.
常见从属连词：when, while, as, before, after, until, till, since, if, unless, so that, because, although 等
常见并列连词：and, or, but, yet, for, either…or, both…and, not only…but also, as well as, neither…nor 等
① <u>When he comes</u> I'll tell him about it.
② I wasn't long <u>before he told us about it</u>.
③ We <u>danced and danced</u> <u>until they all joined in</u>.
④ He was worried <u>because he hadn't had any letter from her</u>.
⑤ <u>Although everyone played well</u>, we lost the game.
⑥ We were <u>singing and dancing</u> all evening.
⑦ She has been learning English for six years, <u>but she doesn't speak it very well</u>.
⑧ The days were short, <u>for it was now December</u>.