物质的俗称与化学式不相符合的是（　　）

A．熟石灰 Ca（OH）₂

B．纯碱 NaOH

C．干冰CO₂

D．胆矾 CuSO₄•5H₂O

—Haven’t you seen the speed limit sign? Please drive     .

—Sorry,but I have to.

A．more slowly a bit

B．slowly a bit more

C．a bit more slowly

D．slowly more a bit