I went to school ______ my father’s car yesterday. [ ]

Why didn’t you call me this morning?——I ______ call you. I called you all the morning, but I couldn’t ______.

My brother likes math ________ chemistry. [ ]

_____ do you telephone your parents? — Once a week, at least. [ ]

It is reported that _______ people in the world are suffering from the H1N1 flu.