感染了华支睾吸虫后发病与否取决于()
A.成虫寄生部位
B.华支睾吸虫的毒力
C.虫的种类不同
D.成虫寄生在胆管中的数量
E.机体抵抗力
参考答案:D
—Liu Xuan, did you see the Denmark’s famed “Little Mermaid” sculpture in Shanghai Expo?
—No, I didn’t. I _______ it twice in Denmark.
A.have seen
B.were seeing
C.had seen
D.saw
下列能产生自溶酶的细菌是( )
A.肺炎克雷伯菌B.肺炎链球菌C.金黄色葡萄球菌D.卡他布兰汉菌E.草绿色链球菌