关于混凝土表面碳化的说法，正确的有（）。A.降低了混凝土的碱度  B.削弱了混泥土对

事情过了这么久，______的情况我哪里会记得呢

A．到时

B．这时

C．那时

D．此时

--They ________ out the problem, but failed.

--What a shame ! I never thought it was going to happen like that.

A．managed to work

B．managed working

C．sought working

D．sought to work

When the teacher told the boy to sit down, he _____ to her and said she couldn't make him.

A．gave way

B．talked back

C．looked up

D．got down

下列关于甲状舌管囊肿的临床特点，错误的是（）

A.是较常见的先天性疾病

B.在颈前中线的任何部位发生大小不一的囊性肿块，多呈圆形，质地较软，光滑，边界限清楚，B超检查有助诊断

C.并发感染时囊肿可增大、疼痛，破溃后可形成瘘管

D.一般不随吞咽及伸舌而上下移动

E.手术切除不彻底容易复发

治血热扰心，高热烦燥，心神不安者，宜选用的药物是（）

A.川芎

B.延胡索

C.郁金

D.丹参

E.虎杖