无锡城市发展迅速，目前地铁1、2号均已全线开通．小霖去乘坐地铁时发现“聪明的电梯”（如图甲），小霖根据网络搜索的如有乙图所示的简易控制电路，R是一个压敏电阻，其电阻阻值随压力的增大而减小．分析：当人走下电梯后，电磁铁的磁性变____ （选填：“强”或“弱”），电动机的转速变____ （选填：“大”或“小”）．

平面直角坐标系内的点A（﹣1，2）与点B（﹣1，﹣2）关于（  ）

补全对话。
A: What bad weather! Another sandstorm begins.
B: So it is. But why are there so many sandstorms recently?
A: Because there is so much sand around us.
B: Why is there so much sand?
A: Because a lot of land has been____  into sand.
B: And why?
A: Because people have ____  down a lot of trees.
B: That may be the root(根源). We should____  people from cutting down trees. Although we have built “ the Great Green Wall”, we still need to work hard to ____ the environment.
A: I agree ____ you. Let's go to the hill and plant trees on Sunday.
B:Good idea.