1．上皮组织 A．支持、连接、保护、营养 2．输导组织 B．保护内部柔嫩部分 3

The new dictionaries are very useful. They ________ well and ________ already .

A．sell; have been sold out

B．sold; had sold out

C．sell; sell out

D．are sold; have been sold out

I enjoy the street dance “hip-hop”, but _________ my father _________ my mother likes it.

A．both; and

B．neither; nor

C．either; or

D．not only; but also

A． ,.

B．, .

C． , .

D．,.

现实主义文学的特征？

在进行直流锅炉负荷调节时，为什么要严格保持给水量和燃料量的固定比例？