R28是中药学,那么我国著名的《神农本草经》一书,应该属于其中哪个类别中呢()?
A、R281.2
B、R281.3
C、R281.4
D、R281.5
参考答案:A
列举两个例子:说明声音能传递信息或者能量:
例1________________________________________;
例2________________________________________.
You’ve spent too much time _________football.
A.play
B.playing
C.played
D.to play