At ____ present we are going through a hard time, but I’m sure ____ things will get better in the near future.

A．the; the

B．the; 不填

C．不填; the

D．不填; 不填

测定砂浆强度等级用的标准试件尺寸为（）。 

A、70.7mm×70.7mm×70.7mm

B、100mm×100mm×100mm

C、150mm×150mm×150mm

D、200mm×200mm×200mm