单列直插式(SIP)集成电路引脚识别:以正面(印有型号商标的一面)朝自己,()朝下,

题型:填空题

问题:

单列直插式(SIP)集成电路引脚识别:以正面(印有型号商标的一面)朝自己,()朝下,引脚编号顺序()排列。

考点:电子与通信技术电子产品制造工艺电子产品制造工艺题库
题型:填空题

完形填空II. 根据所学语段,用适当的词填空。请同学们务必看清题目要求,限做指定题目。(共8个小题;每小题1分,满分8分)

(长郡生试题)   Another drug that has helped increase the standard of people’s   41  is penicillin. This bacteria-killing medicine is considered by many to be one of the most   42   medicines in contemporary society. It was discovered by   43  Scottish scientist named Alexander Fleming in 1928. He noted that mould had grown on a special transparent jelly that had bacteria on it. Fleming tried this mould   44  on another bacterium and found that it killed the bacteriun   45  . He named the chemical found in the mould ‘penicillin’ and tried to make it pure to be a medicine.

46    , it was not until World War Ⅱ   47  two other scientists managed to use new chemical techniques to purify it. They were able to produce it in large    48   .

题型:填空题

如图所示,在真空室中有一水平放置的不带电平行板电容器,板间距离为d,电容为C,上板B接地。现有大量质量均为m、带电量均为q的小油滴,以相同的初速度持续不断地从两板正中间沿图中虚线所示方向射入,第一滴油滴正好落到下板A的正中央P点。如果能落到A板的油滴仅有N滴,且第N+1滴油滴刚好能飞离电场,假定落到A板的油滴的电量能被板全部吸收,不考虑油滴间的相互作用,重力加速度为g,则下列说法正确的是( )

A.落到A板的油滴数

B.落到A板的油滴数

C.第N+1滴油滴通过电场的整个过程所增加的动能等于

D.第N+1滴油滴通过电场的整个过程所减少的机械能等于

题型:填空题

引起牙髓病的感染途径有

A.源性感染、牙周病逆行感染、深龋和严重的牙体缺损

B.龋病及牙周病逆行感染和化学药物刺激

C.龋病及牙周病的逆行感染

D.外伤和发育畸形

E.物理、化学刺激和全身性疾病

题型:填空题

引起呼吸衰竭的疾病最常见的是()

A.肺炎

B.肺结核

C.自发气胸

D.慢性阻塞性肺疾病

E.肺癌

题型:填空题

把amolNH3、O2组成的混合气充入密闭反应器中,在一定条件下发生化学反应。若混合气中O2的物质的量为x,生成HNO3的物质的量为y。试确定x在不同取值范围时y=f(x)的函数表达式,并画出函数的图象。

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