下列各句，没有语病、句意明确的一句是：（ ）

Smoking is one of the ________causes of cancer，killing millions of people each year.

I hope you have a great trip to Hong Kong. —________.

Excise me, but I haven’t got the iPhone 4 ordered through the Internet. — Sorry, madam, I’m sure you ____ have it by this Friday.[ ]

I’m going to Hangzhou for a holiday this weekend. — ___ you are there, could you buy me some green tea