肺炎链球菌能在肺中存活,并引起肺炎,主要是由于该菌能产生()
A.具抗吞噬作用的荚膜
B.具抗吞噬作用的M蛋白
C.壁磷壁酸
D.C多糖
E.肺炎链球菌溶素
参考答案:A
25. ------- What’s that noise?
--------- Oh, I forgot to tell you. The new machine ____________.
A.was tested
B.will be tested
C.is being tested
D.has been tested
脱氧核酶