填入下面一段文字横线处的语句，最恰当的一句是（ ）有时候我在想，如果一个人能像骆驼一样坚忍不拔，不遗余力，奋力向前，那么你面前就不会有无法跨越的“死亡之海”。你可以蔑视面前的困难和不利的环境， ， ， ，但那沉甸甸的壮丽的旅程，足以使你感叹自己拥有着无悔的人生。

I didn’t watch TV last night, but I did my homework.— __________.

Hi , Lily . How was your trip to Hongkong — ________, We had a good time there.

He failed in finding the job. I think thathe _____to get somemore qualifications before applying for thejob.

The best way to prevent the air polluting _____ , but the sky is still not clear