The young man made a ________ to his parents that he would try to earn his own living after graduation.[ ]

A．prediction  

B．promise

C．plan  

D．contribution

新奥法施工中，第二次衬砌( )。

A．与第一次衬砌共同受力
B．基本上不承载
C．单独承载
D．有限制的承载