《建筑设计防火规范》规定，人员密集的公共场所、观众厅的疏散门不应设置门槛，其净宽度不应小于()，且紧靠门口内外各()范围内不应设置踏步。

A.1.2m；1.2m

B.1.2m；1.4m

C.1.4m；1.4m

– Could I use your mobile phone? I have to call my mom for the coming class meeting.

--Yes, of course you _____________.

A．must

B．can

C．need

D．will