患者女，70岁，上下颌牙列缺失，行全口义齿修复，支架试戴正常，排牙充胶，采用微波聚合，戴牙时发现塑料基托与黏膜不密合，而金属基托未见异常。

由于充填造成支架移位的原因是 （）

A.装盒石膏包埋过多

B.支架焊接移位

C.塑料充填过早

D.塑料充填过迟过多

E.塑料充填时带入气泡

----Have they finished the project?

---- Yes. By the end of last month, they ______ it. Now they ______ on a new one.

A．had finished; are working

B．had finished; work

C．have finished; are working

D．have finished; work