某包工包料工程合同金额3000万元，则预付款金额最低为( )万元。
A．150
B．300
C．450
D．900
参考答案：B
E-mail, as well as telephones, _____ an important part in daily communication.
A．is playing
B．have played
C．are playing
D．played
金字塔建筑成就
