—Is this your bike?—No, . It’s bike.A. it is, Li Lei’s B. this is, Li Lei C. it isn’t , Li Lei’s
Sunglasses are used ________ protecting your eyes in sunny days.
Leo was late for class again. So he____ clean the classroom after school.
His wife advised him________ drinking, but he wouldn't.
That beautiful skirt is _____ cotton.
— Why _____ most stars _____ in the daytime? — Because the sun is too bright.