题目

That was not the first time he ______ us. I think it's high time we _______ strong actions against him. A. betrayed (背叛), take       B. had betrayed, took   C. has betrayed, took         D. has betrayed, take 答案：B  一同学家里电度表的读数原是，现在他家里有40W的电灯4盏，60W的电灯2盏，平均每天使用3h，使用30天，共用________度电，此时，电度表的读数应为________。