按注音写词语。
gē bì
liáo liàng
hào hàn
gān hé
róng yán
____
zhù lì
zhèn chàn
péng pài
huì xīng
fán zhí
— There's wrong with my chair. Can you mend it?— No problem.
What made the children ____ (laugh) loudly?
读图,完成下题.
如图甲所示,在匀强磁场中,一矩形金属线圈两次分别以不同的转速,绕与磁感线垂直的轴匀速转动,产生的交变电动势图象如图乙中曲线a、b所示,则( )