【简答题】如图2-1所示,A为通流截面可变的节流阀,B为溢流阀。溢流阀的调整压力为p Y ,如不计管道压力损失,试说明,在节流阀通流截面不断增大时,液压泵的出口压力如何变化?
【单选题】1单位时间内流过某通流截面的液体( )称为流量。
【单选题】设机器字长为16位,存储器按照字编制,对于单字指令而言,读取该指令后,PC自动加___。
【简答题】金属丝应变片和半导体应变片比较其不同点是 ,材料的电阻率相对变化为辅;而半导体材料则正好相反,其应变效应以机械形变导致的电阻率的相对变化为主,而机械形变为辅。
【单选题】患者女,32岁。医嘱行 I甲状腺功能测定,护士指导该患者在试验期间应忌食的食物有
【单选题】Why did the speaker think it was a good film for the girls?
A.
Because she liked it at their age.
B.
Because it was a story about animals.
C.
Because it was a funny story.
【简答题】Li Hua, I feel great honored to be trusted with your personal affairs. Here is some advices for you: First of all, you should talk to your parents or let them know where your interest is. If they know...
【单选题】Gram positive cells have a
A.
second outer membrane that helps to retain the crystal violet stain
B.
multiple layer of peptidoglycan that helps to retain the crystal violet stain
C.
thick capsule that traps the crystal violet stain
D.
periplasmic space that traps the crystal violet