Ken _____________ go swimming next Monday.[ ]
A. isn't
B. won't
C. was
D. wasn't
答案:B
介导转导的物质是()
A.性菌毛
B.噬菌体
C.R质粒
D.F质粒
E.Vi质粒
作为蠕虫的中间宿主 ()
A.锯齿华溪蟹
B.中华白蛉
C.红斑蛛
D.热带臭虫
E.人疥螨