Ⅰ. 单项选择 (30分)
( )1. Usually the pollution in big cities is much more serious than ________ in the countryside.
A. one B. it C. this D. that
( )2. His father can’t come back home _______ the heavy snow.
A. because B. because of
C. since D. but
( )3. —Have you read this book _______ ?
—Not _______ .
A. already; yet B. yet; already
C. already; already D. yet; yet
