题目

如图甲所示，线圈的匝数n=300匝，横截面积S=50cm2，线圈总电阻r=100Ω，沿轴向有匀强磁场，磁场的磁感应强度随时间按如图乙所示规律变化，则（ ）A. 若在a、b间接一个理想电流表时，第末电流表的示数为B. 若在a、b间接一个理想电流表时，第末和末的电流方向相同C. 第1s末a、b间电压为零D. 第末a、b间电压比末的小阅读下面材料，在空白处填人适当的内容（不多于3个单词）或括号内单词的正确形式。Lala accelerated her walk up the path to the caves, fearing that there might be wild beasts 1. (lie) in wait for her. She had no man 2. his spear to protect her. She had almost reached her destination 3. a delicious smell arrested her progress and she stopped. Her senses became 4. (dizzily)with hunger. She could see her mother and the older children 5. (prepare) the deer and pig meat over the fire. Her aunts were making6. (cloth) with animal skins. Abruptly she 7. (sit) down, only to 8. (scoop) by her laughing, shouting sister, Luna. Lala smiled with 9. (relieve). It was good 10.(have) her family around her.