【简答题】Twisted pairs can be used for transmitting either ____or digital signals.
【简答题】A、B两种哺乳动物体重相似。若每天每只消耗100g大麦(含65%淀粉和35%脂肪)。已知每克淀粉、脂肪完全氧化分解时分别产生0.55g和1.05g的水。两种动物在相同的环境下分别持续实验10d,得到下表数据。 (1).为维持水代谢平衡,每天应给两种动物的每只个体提供多少水? A:________________________________________________; B:________...
【单选题】Voltage is taken as an( )variable, and so voltage is measured by always connecting the voltmeter( )an element or( ) two points in a network.
A.
across, across, between
B.
across, through, between
C.
through, across, across
D.
through, through, between
【简答题】肥胖是人类健康的大敌,跳绳是减肥的方法之一.某人的质量为80千克,跳起时重心升高的平均高度约为5厘米.在晨练中,他在10分钟内跳了800次,请问在10分钟时间内: (1)人克服重力所做的功是多少? (2)人克服重力做功的平均功率是多少? (3)假如人克服重力做功而消耗的能量只由脂肪提供,在理论上可以消耗多少脂肪?(每千克脂肪提供的能量是1.6×10 7 J,可用q=1.6×10 7 J/kg表示,...
【单选题】The direction of current is conventionally taken as the direction of:
A.
positive charge movement
B.
negative charge movement
【单选题】As a general rule, the first troubleshooting action to be taken in checking faulty electric control devices is to ______. prefix="o" ns="urn:schemas-microsoft-com:office:office" ?xml:namespace>
A.
draw a one line diagram of the circuitry
B.
test all fuses and measure the line voltage prefix="o" ns="urn:schemas-microsoft-com:office:office" ?xml:namespace>
D.
insulate the apparatus from ground prefix="o" ns="urn:schemas-microsoft-com:office:office" ?xml:namespace>
【单选题】As a general rule, the first troubleshooting action to be taken in checking faulty electric control devices is to ().
A.
draw a one line diagram of the circuitry
B.
test all fuses and measure the line voltage
D.
insulate the apparatus from ground