将计算机分为286,386,486,Penfium,是按照
A.CPU芯片
B.结构
C.字长
D.容量
参考答案:A
解析: 微型计算机按CPU芯片分为286机、386机……
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. _______
(10分)一个200匝、面积为20cm2的线圈,放在磁场中,磁场的方向与线圈平面成30°角,若磁感应强度在0.05s内由0.1 T增加到0.5T,在此过程中磁通量变化了多少?磁通量的平均变化率是多少?线圈中感应电动势的大小是多少伏?