选择质控血清的原则()A．瓶间差异极小 B．大瓶包装 C．分析测试项目应满足需要 D

I’m stuck is used __________.

A. when you have a good idea    

B. when you go on talking without stop

B. when you are thinking something is too easy

D. when you can’t continue with something because it’s too difficult

北极地区气候寒冷，生活在这些地区的因纽特人为了适应这里的环境，修建了：

A．窑洞　

B．冰屋　

C．高架屋　

D．四合院

胃、十二指肠溃疡并发出血均需外科治疗。

下列属于流动资产的有（）

A、预收账款

B、预付账款

C、应收账款

D、应收票据

An instructor scored a student’s test of 50 questions by subtracting 2 times the number of incorrect answers from the number of correct answers. If the student answered all of the questions and received a score of 38, how many questions did that student answer correctly ？（）

A.19

B.38

C.41

D.44

E.46