How many ____________ do you have?[ ]
A. books
B. a book
C. the book
答案：A
A．速度变化越大，加速度就越大
B．速度为零时，加速度一定也为零
C．加速度的方向不变，速度的方向也一定不变
D．速度的变化率越大，加速度就越大
The building around the corner caught fire last night. The police are now _____ the matter. [ ]
A. seeing through
B. working out
C. looking into
D. watching over
