阅读理解。
Tomorrow is Sunday. I'm not going to work. I'm twenty-two. My little brother isn't going to
school. He is ten years younger than I am. I'm going to do some shop- ping. My brother is going to
do his homework. My parents are going to work. My father is going by bike and my mother by bus.
In the aftemoon, I'm going to the park with my brother. We're going on foot. We're coming home at five.
My parents are going to get home at half past five. We must help my mother cook the dinner. After
supper, I'm going to dance with my friends, and my brother is going to watch TV with my parents.
1. My brother is _____.[ ]
A. ten
B. twelve
C. twenty-two
D. thirty-two
2. My father is going to work _____.[ ]
A. by bike
B. by subway
C. by bus
D. on foot
3. My brother and I _____ to the park in the afternoon. [ ]
A. are driving
B. are riding
C. are walking
D. are flying
4. My father and mother are coming back at _____, [ ]
A. 7:30
B. 4:30
C. 6:30
D. 5:30
5. I'm going to dance _____. [ ]
A. at 6:30
B. at 7:30
C. after 7:30
D. after supper
的速率反向弹回，而B球以
的速率向右运动，则B的质量mB=_______；碰撞过程中，B对A做功为 。
