气血周流循行并输布弥散于全身要靠()。
A、上、中、下三焦
B、胃气
C、经络
D、经络之气
E、气海
参考答案:C, D
Mr. Wang, who is said to have immigrated to the USA, __ at No.2 Middle School in our city for twenty years.
A.has been teaching
B.was teaching
C.taught
D.has taught
教室里的日光灯是串联的还是并联的?某班的教室里共有8盏40W的日光灯,40W的日光灯工作时的电流为180mA,则8盏日光灯全部工作时,通过的总电流为多少A?