营养性污染物主要是()和()。
参考答案:氮、磷化合物;NH3-N、TP
____in this display is on sale for half price.
A.Each furniture
B.Each piece of furniture
C.A furniture
D.Two pieces of furniture
干菜在食用前需要用水( )
A.浸发
B.煮发
C.碱发
D.油发