正常菌群对构成生态平衡起着重要作用,下面描述其生理学意义中错误的是()
A.生物拮抗作用
B.营养作用
C.免疫作用
D.维持肠道的渗透压
E.抗衰老作用
参考答案:D
I'd like to buy a big and modern house. _____, I hope it's in a quite neighborhood. [ ]
A. After all
B. Above all
C. As a result
D. At that moment
飞行员在做特技飞行时,感觉“大地迎面扑来”,这是以______参照物的.