A:家用冷暖空调的功率约为 200W
B:一个机械经改进后其效率可达 100%
C:一名中学生从一楼登上三楼克服自身重力做的功约为 300J
D:家用电饭锅正常工作时的电流约为 4A
下图告诉我们( )
______ it eat grass? ( )
She_______ Japanese when she was in Japan. Now she can speak it freely.