Since David ________ downloaded a virus into his computer，he can not open the file now[ ]

I wonder if you could go with me to the supermarket.—Sorry. I _______ my experiment report all the morningand haven’t finished yet.

The Apple founder and former CEOJobs（乔布斯） ________on Wednesday at the age of 56.

.Not until today ___ a stage___ we have enough right to deal with everything

What’s wrong with your car? – Well, as you know, cars usually_______start in winter.