如图所示，一个变压器原副线圈的匝数比为3∶1，原线圈两端与平行导轨相接，今把原线圈的导轨置于垂直纸面向里、磁感应强度为B=2T的匀强磁场中，并在导轨上垂直放一根长为L=30cm的导线ab，当导线以速度v=5m/s做切割磁感线的匀速运动时（平动），副线圈cd两端的电压为____ V。

    Since my mother moved to live with us in the city, she has been much heavier than before. As time went by, her health got1. So I had to take her to see a2. My mother was told to lose weight by doing exercise every day. She had no choice but to follow3the doctor said. I told her that I would exercise with her every morning.

    On the first morning, she got up very early4ran with me in our neighborhood. I tried to run slowly so that she could follow me. After5for some minutes, I told her the proper ways of exercise and the importance of eating healthy food. She listened to me carefully. It made me6that she told me everything very patiently when I was a kid. On the second morning, I praised her for keeping running with me.

    But after two weeks, she wanted to7running because she thought the two-week exercise didn't work at all. To encourage her, I taught her how to use the facilities (设施) for exercise in our8. She began to exercise again.

    With my help, it9her one month to develop a good habit of daily exercise. "Thank you, my dear daughter. Exercise brings health and happiness to me. I will10worry about my health." Her words touched my heart deeply. I felt happy to make a big difference to my mother's life.

—There is one ____ (dress).

资料1:苏云金芽孢杆菌是一种细菌，体内有“杀虫蛋白”基因（简称BT基因）。将该基因转入水稻中，可以生产出含有BT蛋白的大米，名为BT大米。BT蛋白能使食用它的昆虫幼虫死亡，但目前尚未发现BT蛋白对哺乳动物有明显的毒害作用。

资料2:—般来说，DNA和蛋白质彻底分解成小分子物质后才能被吸收，即使食用了BT 大米，人体内也不会有BT基因和蛋白。然而，近年来科学家发现，存在未经消化的蛋白质被吸收进入人体的现象。