根据短文内容，用方框中所给单词的适当形式填空，每词限用一次。

Do you love animals? Would you like to keep animals as a pet? Nowadays, many people like to keep pets at home. The most popular _____小题1:____ are cats and dogs. They are friendly to people, and they are also ___小题2:_____ to take care of. Some people like parrots as pets. Pets lovers will ____小题3:__lots of things for their pets, such as beds, clothes and even toothbrushes. Pets are very useful, too. The people who can’t hear need the dogs’ help to answer the door. And the people who live _____小题4:____ should keep a pet if he wants to be healthier and ___小题5:_____. If you have pets, don’t forget to spend more time with them. They need love, too.

一理想变压器的原线圈接一电流表,副线圈接入电路的匝数可以通过触头Q调节,如图.在副线圈输出端接了定值电阻R0和滑动变阻器R,在原线圈上加一电压为U的交流电,则(  )

A．保持Q位置不动,将P向上滑动时,变压器的输出电压变化

B．保持Q位置不动,将P向上滑动时,电流表的读数变大

C．保持P位置不动,将Q向上滑动时,电流表的读数变大

D．保持P位置不动,将Q向上滑动时,变压器的输出功率不变