正常脾静脉的内径为（）
A.2～4mm
B.3～5mm
C.5～7mm
D.7～11mm
E.8～12mm
参考答案：C
如图所示是汽车的速度计，某同学在汽车中观察速度计指针位置的变化。开始时指针指示在如图甲所示位置，经过5s后指针指示在如图乙所示位置，若汽车做直线运动，那么它的加速度约为
A．1.6m/s2
B．2.2m/s2
C．5.1m/s2
D．8.0m/s2
下列各句的A、B、C、D中有一处错误，请在不改变句子意思的前提下，将正确答案写在题后的横线上。
1. Please tell him don't to be late for school. 1. _______
A B C D
2. Kitty's uncle has gone to Beijing twice. 2. _______
3. We don't know what to solve these problems. 3. _______
4. It's very nice for you to bring me the newspapers and magazines. 4. _______
5. The scientists are wondering whether can people grow plants on Mars. 5. _______
