下述关于覆覆盖意义说法错误的是()
A.保持牙列完整
B.提高了咀嚼效能
C.扩大了咀嚼面积
D.保护舌侧软组织
E.保护唇、颊粘肌
参考答案:A
—The concert hall is large enough to hold more than 2,000 people.
—______. Did you say 2,000?
A.Excuse me
B.I’m sorry
C.What a surprise
D.What a shame
天然气的危害性分别是化学活波性、易扩散、腐蚀性、毒害性、带电性。