A:turn out
B:bring out
C:call out
D:pick out
小敏想借助如图所示的电能表测量家用电器的功率,除了电能表外,还需要的测量工具是____。测量时,关掉其它所有用电器,只让一盏灯正常工作,测得电能表转速为5r/min(1min内电能表转盘转5r),则这盏灯的电功率为____W。
–Are you free tonight?
—Sorry, but I'm not . I've got so much homework to do.
读图回答下列问题: