Professor Williams keeps telling his students that the future________ to the well­-educated.

A．is belonging

B．is belonged

C．belongs

D．will be belonged

北京某装潢公司通过电子邮件向福建材料公司订购一批装潢材料，此要约的生效时间为( )。

A．写邮件时

B．邮件进入福建公司的制定邮箱时

C．确定购买意向时

D．福建公司发货时