确保压风机正常工作，贮气罐内气压不低于（）MPa且气路畅通。
A、0.5
B、0.8
C、1.0
D、1.2
参考答案：B
革兰染色所用染料的顺序是（）
A.稀释复红－碘液－乙醇－结晶紫
B.结晶紫－乙醇－碘液－稀释复红
C.结晶紫－碘液－乙醇－稀释复红
D.稀释复红－乙醇－结晶紫－碘液
E.稀释复红－结晶紫－碘液－乙醇
14. — Excuse me. Do you happen to have change for a 50-pence piece?
— __________. I’ve just used up all my coins.
A．I don’t believe so
B．I can’t agree more
C．I’d rather not
D．I’m afraid not
