【多选题】下列有关PCR技术的叙述不正确的是
B.
基因探针是指用放射性同位素或荧光分子等标记的DNA分子
【单选题】With reference to an axial piston pump, which one of the following statements is true?
A.
The cylindrical barrel is coupled to the motor
B.
The cylindrical barrel has an odd number of bores
C.
The bores end in sockets
D.
The sockets fit in the swash plate
【单选题】The delivery rate of a variable stroke axial piston hydraulic pump is controlled by varying the position of the _____.
【单选题】下列有关同位素标记相关实验的叙述,正确的是
A.
用含 32 P 的培养液培养噬菌体,一段时间后,其子代噬菌体中可检测到放射性
B.
用含 3 H 的亮氨酸培养大肠杆菌,一段时间后,可依次在核糖体、内质网、高尔基体中检测到放射性
C.
用含 14 C 的 CO 2 培养蓝藻,一段时间后,可在其叶绿体基质中检测到( 14 CH 2 O )
D.
用含 18 O 的 H 2 O 培养小球藻,一段时间后,可在其叶绿体基质中检测到( CH 2 18 O )
【判断题】在AutoCAD中使用块BLOCK命令定义的内部图块,只能在定义它的图形文件内自由调用。
【单选题】In a fixed displacement axial piston hydraulic motor, the speed is varied by .
A.
regulating the ratio between torque and speed via the torque limiter at the motor
B.
directing the motor output flow through a bypass line
C.
maintaining a constant flow and pressure input
D.
controlling the input flow rate
【单选题】一个项目由三个活动组成。A活动历时5周,B活动历时6周,C活动历时7周。活动排序为A-B-C。但是,活动B的资源分配要1周,C在B活动开始1周后开始。则该项目最短工期是多少?()
【单选题】Displacement of axial piston pumps are controlled by
C.
eccentricity of the rotor
【单选题】关于“仁”的具体实践要求,不包括以下哪项?