Carbondioxide from burning fuels is the most common ofthe so-called greenhouse gases. A．produced B．producing C．to be produced D．havingbeen produced

I have got a bad cold.-No wonder you _______these days.

She_______ Japanese when she was in Japan. Now she can speak it freely.

, you seem to be a little absent-minded. What’swrong—Oh, sorry. Actually, Iofthe family party this weekend. I have to make a list of what needs to bebought.

___________Mr Zheng ___________ Beijing last week— No, but he ___________ Beijing with his son next year.