大肠杆菌中选择性标记一般为______；酵母菌中选择性标记一般为______。
参考答案：抗生素抗性基因 营养缺陷型
可发生Ⅰ型呼吸衰竭的是（）
A.慢性阻塞性肺病
B.肺炎球菌性肺炎
C.局限性肺不张
D.肺栓塞
E.早期肺癌
–How can I make fewer mistakes in the exams?
–Try to be careful. _______ careful you are, _______ mistakes you will make.
A．The more ; the fewer
B．The more ; the less
C．More; less
D．More; fewer
