问题 选择题 Read and choose. (在每组单词中找出不属于同类的一顼，写在题前括号内)( )1. A. went ( )2. A. read ( )3. A. fishing ( )4. A. yesterday( )5. A. flew B. clean B. stay B. visit B. fun B. played C. played C. newspaper C. hiking C. tomorrow C. watched D. washed D. go D. swimming D. today D. visitd 答案 1.B 2.C 3.B 4.B 5.A
=20Ω，R=30Ω，电源电压保持9V不变，当滑动变阻器滑片P在a端时，电压表的示数是 V，电流表示数是 A，滑动变阻器滑片P移到b端时，电压表的示数是_______V，电流表示数是 A。