You have seen Helen in her office this morning because she’s been out of town for two weeks.

I do some explanations I________ to call on you yesterday,but someone came to see me justwhen I was about to leave

If we ______ develop the world successfully, we must make sure that everyone is able to take partin the new world we create[ ]

They didn’t buy the car._____ , they didn’t like its color；_____ , it was too expensive.[ ]

I like that green T—shirt. ________ is it—It’s fifteen dollars.