I think the most helpful invention is light bulb. It seeing in the dark, and it gives people more time to work and play every day.A. used to B. is used to C. is used for
Helen caught a cold the day before yesterday. But she’s ______ today.
—How many students are there in your school? —About_______ students, I think.
Tom is ______ of the six boys.
——Must I take the medicine every day?—No, you _______.
—I looked for you in the office, but I could’t find you. —Oh, I in the library