—Why do you look worried?—Fred left the company half an hour ago. His work ________ unfinished since.

—I remember I left my laptop in the study last night. Why ________ here? —Oh, I thought you might need it so I brought it here for you.

He couldn’t stand the noise made by the factory, so he wrote a letter to the newspaper to _________ about it. 

—I’m losing my eyesight, I’m afraid.—To finish this book, you ______ in front of your computer too long.

When winter comes, it _________ become very cold in Shenyang.