Because of the bad management, this restaurant was not _______ it was 10 years ago.

A．half as good as what

B．as half good as that

C．as good as half what

D．half as good as that

碳酸铵[(NH₄)₂CO₃]在室温下就能自发地分解产生氨气，对其说法中正确的是 [ ]

A．其分解是因为生成了易挥发的气体，使体系的熵增大

B．其分解是因为外界给予了能量

C．其分解是吸热反应，据能量判据不能自发分解

D．碳酸盐都不稳定，都能自发分解