下列哪些药物可抗疟原虫（）
A.磷酸氯喹
B.甲氟喹
C.青蒿素
D.氯喹注射液
E.氟哌酸
参考答案：A, B, C, D
Many British people have noticed that butterflies _______ from its natural habitats during the past several years.
A．are disappearing
B．have been disappeared
C．have been disappearing
D．will have disappeared
如果用户希望在网上聊天，可以使用的因特网的服务形式是( )。
A．电子邮件服务
B．新闻组服务
C．电子公告牌服务
D．搜索引擎服务
