the first / second ... last time; immediately/instantly/ directly

eg: The first time I went abroad I could hardly understand what the foreigners said.

The moment I saw him, I knew what had happened.

3. It seemed that the water was to blame.

be ﹢动词不定式，可以表示该做或不该做的事

be to blame 应该负责；应受责备

eg: No one is to leave this building without the permission of the police.

You are not to drop litter in this park. 公园里不许乱丢垃圾。

Who is to blame for the fire?

Who is to be responsible for this?

4. Only if you put the sun there did the movements of the other planets in the sky make sense.

only ﹢加状语放于句首时，主句用部分倒装。

eg: Only a week later did I receive an answer from her.

Only when you are forty and looking back will you realize that you haven't done your best.

拓展：only if 可译为"只有"

eg: Only if you study hard, will you pass the test.

Make a call only if it is important.

5. The first suggested that cholera multiplied in the air.