某一实验装置如图所示，在铁芯上绕着两个线圈P和Q，如果线圈P中的电流i随时间t的变化关系有如下图所示的四种情况，则可以在线圈Q中观察到感应电流的是
It’s 12 o’clock at noon. He’s having ____________.
What do you ____________ for lunch today?
Don’t ____________ the window, please!
There aren’t ____________ ricers in the park.
There are many ____________ rivers in the park.
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