引起恶性疟疾发作不规则的主要原因是()
A.恶性疟原虫侵犯各期红细胞
B.疟原虫释放毒素
C.恶性疟原虫在红细胞内发育时间不一致
D.粘附在血管内的疟原虫再度侵犯新的红细胞
E.潜伏在肝脏中的裂殖子侵犯红细胞
参考答案:E
引起恶性疟疾发作不规则的主要原因是()
A.恶性疟原虫侵犯各期红细胞
B.疟原虫释放毒素
C.恶性疟原虫在红细胞内发育时间不一致
D.粘附在血管内的疟原虫再度侵犯新的红细胞
E.潜伏在肝脏中的裂殖子侵犯红细胞
参考答案:E
完形填空。 | |||
Television has now come to nearly every family. It has __1__ a very important part in __2__ life. School children in the USA watch TV about twenty-five hours a __3__. Some parents feel the television is good __4__ their children because it helps them learn about their country and the world. __5__ the help of some programme (节目) of education (教育), children do __6__ school. __7__ parents do not let their children __8__ TV too much. They say the TV programmes are not good and children __9__ bad things from them. Men have invented many things which have brought much convenience (方便). Television is one of them. If it __10__ carefully planned, watching TV can be good for children. | |||
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