Pompeii _______ by so many tourists that some of the relics are not well protected.

A．has been visited

B．is visited

C．is visiting

D．was visited

关于脚手架的拆除说法正确是（）。

A.拆除前应对施工人员进行交底

B.单、双排脚手架拆除作业必须由上而下逐层进行，严禁上下同时作业

C.应拆立柱再拆大横杆

D.拆除的构配件应由垂直运输设备向下运送，严禁直接抛掷至地面

E.连墙件必须随脚手架逐层拆除，严禁先将连墙件整层或数层拆除后再拆脚手架