a. 表示现在( 指说话人说话时) 正在发生的事情。
b. 习惯进行:表示长期的或重复性的动作,说话时动作未必正在进行。
Mr. Green is writing another novel.
She is learning piano under Mr. Smith.
c. 表示渐变的动词有:get, grow, become, turn, run, go, begin等。
The leaves are turning red.
It's getting warmer and warmer.
d. 与always, constantly, forever 等词连用,表示反复发生的动作或持续存在的状态,往往带有说话人的主观色彩。
You are always changing your mind.
My dictionary ___, I have looked for it everywhere but still___ it.
A. has lost, don't find B. is missing, don't findC. has lost, haven't found D. is missing, haven't found.
答案D. 前句是一个仍在持续的状态,应用进行时,由于没有找到,其影响仍然存在,应用完成时,瞬间动词用于否定式时可用于完成时。
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