成人粪便中主要的菌群约占
A.20%B.40%C.60%D.70%E.80%
参考答案:E
解析:成人粪便中主要的菌群是大肠埃希菌、肠球菌和厌氧菌,约占80%。
Since David ________ downloaded a virus into his computer,he can not open the file now.[ ]
A.readily
B.accidentally
C.horribly
D.irregularly
中唐古文运动的倡导者是()。
A.韩愈与刘禹锡
B.柳宗元与刘禹锡
C.韩愈与柳宗元
D.白居易与刘禹锡