天然气管道线路“三桩”通常指()。
A.里程桩、加密桩、穿越桩
B.里程桩、转角桩、标志桩
C.转角桩、加密桩、穿越桩
D.标志桩、里程桩、穿越桩
参考答案:B
– I’m sorry I didn’t attend your birthday party because my mother was ill.
-- ________. Is your mother better now?
A.Forget it
B.Go ahead
C.Come on
D.Take your time
外渗性黏液囊肿常由( )所致
A.外伤
B.炎症
C.过敏
D.感染
E.化学刺激