有一个干电池,当外电阻为1Ω时,电流为1A,当外电阻为2.5Ω时,电流为0.5A,电池的内阻是()。
A.0.25
B.1
C.0.5
D.1.5
参考答案:C
单词拼写.(根据首字母或汉语提示,每空填写一词)(10分)
小题1:There is no (可能) that the crisis will be over in a short time.
小题2:It is u to treat girls and boys differently.
小题3:His first speech as president made a strong i on his audience.
小题4:In front of the village lives a foreign j (记者).
小题5:I bought this house for it’s .(方便)
小题6:She lives in a pleasant neighborhood and enjoys her s (环境).
小题7:When I saw the new freshmen, my own first day at high school (闪现) into my mind.
小题8:He’s (连续不断)disturbing me.
小题9:A medical team c of fifteen doctors has been sent to the front.
小题10:The old man who happened to see the accident gave a brief (描述)of what happened.
小儿腹泻时口服补液盐(ORS液)的电解质渗透压是含钠液的
A.1/4张B.1/3张C.2/5张D.1/2张E.2/3张