与“汽油和汽车”的关系不同,皮鞋和布鞋是________,需求变化________[ ]
A.互为 反向
B.是互补商品 同向
C.互为替代品 同向
D.是互补商品 反向
答案:A
用所给动词的适当形式填空。
1.Listen! How wonderfully the girls _________ (sing)!
2.Simon will leave here if he _________ (finish) the work tomorrow.
3.________ you ________ (go) to the World Park in Beijing next week?
4.—What did you do last night?
—I _________ (write) a letter to my parents.
5.The zookeeper told them __________ (not leave) litter there.
白色血栓的主要成分是()(P236-4)
A、血小板和白蛋白
B、血小板和纤维蛋白
C、血小板和红细胞
D、血小板和白细胞
E、纤维蛋白和白细胞