下列各句中没有语病且语意明确的一项是（ ）（3分）

About one third of the population in Shanghai _____ netizens, while in less developed areas, only three percent ___ online.

You should make it a rule to leave things _______ you can find them again.

I’ll be home late tonight.—Well, _____, I won’t cook dinner.[ ]

The reason __________ she gave for not finishing the homework is that she was ill