You _______ smoke .You are only 14 and it isn’t allowed.A. don’t have toB. mustn’tC. needn’t
It takes my mother one hour ______ to work A. go B. to go C. going
I often go to school ______. A. by bus B. by buses C. by a bus
It’s important _______ us __________English well. A. of, learning B. for, to learn C. of, to learn
I spent three hours_____ this book. A. finish reading B. to finish reading C. finishing reading
——What are you doing _______ vacation? A. to B. for C. at