I have made ______ clear that all of us are strongly against smoking in the office.

A．this

B．it

C．that

D．one

区分左、右肝叶的标志有（）①肝正中裂②肝中静脉③静脉韧带④镰状韧带

A.①

B.①②

C.③

D.③④

E.④