【单选题】原料中的无机成分有游离型和结合型之分,后者在微生物的作用下,可变为()被微生物利用。
【判断题】反转录反应的模板可以是总RNA,也可以是mRNA
【判断题】电弧电压主要由弧长决定,它是指从熔化的焊条顶部到熔池表面最短的距离。
【单选题】Using the definition of unemployment, which of the following individuals would be unemployed?
A.
A full-time student quits school, enters the labor market for the first time, and searches for employment.
B.
Because of the increased level of automobile imports, an employee of General Motors is laid off but expects to be called back to work soon.
C.
Because of a reduction in the military budget, your next door neighbor loses her job in a plant where nuclear warheads are made and must look for a new job.
D.
All of these individuals are unemployed.
【单选题】( 1 )下列哪一种病理表现是儿童急性链球菌感染后肾小球肾炎的病理特点?( )
【多选题】下列属于轴上零件周向固定方法的有( )。