题干
---Thank you very much.
---_________
A：Welcome!
B：You are welcome
C：Sure
D：Of course
答案(点此获取答案解析）
B
---Thank you very much.
---_________
A：Welcome!
B：You are welcome
C：Sure
D：Of course
C(g)+D(g)，当下列物理量不发生变化时，能表明该反应已达到该条件下的最大限度的是