中考
inished C. finishes D. is finished ( )14. _________ wonderful music he is playing ! All of us are losing ourselves in the songs . A. How B. What a C. How a D. What ( )15. It39。 s ________ hard
C. opened D. closed ( )13. It is _______to work out this problem. You needn39。 t go to the teacher. A. enough easy B. easily enough C. easy, enough D. very easily ( ) Our holiday was _______. Yes,
doctor. A. laid B. lay C. lain D. lied ( ) 12. We can see ten ______ people doing morning exercises there at the square every day. A. hundred B. hundreds of C. hundreds D. hundred of ( ) 14. Though
) teacher told us ______ Exercise 1 in our exercise books. A. do B. to do C. doing D. does ( ) found _____ very difficult to learn maths well. A. what B. it C. that D. this ( )39。 m ______ to trouble
. what colour is the carpet D . is the carpet what colour （ ） late, he quietly sat at the back, ________ his notebook and began to write. A. took away B. took down C. took off D. took out （ ） 13. I
kilos C. One kilo and half D .One and half kilo ( ) you know the girl ________ the pink dress? A .on B. putting on C. having D. wearing ( )14. It39。 s ____ hard problem for the two students that ____
C. they D. it ( )12. He asked me where during my trip in Soul. had gone B. had I stayed C. did I have D. I had been ( )13. A traffic jam stopped me _____ here on time A. e B. from ing C. to e D. came
值，若不存在，请说明理由。 略解：（ 1）将 ②代入①化简，由 0021xx n ＜ 21 且 n ≠ 0 （ 2）利用根与系数的关系得：2 )1(4 n nm （ n ＜21且 n ≠ 0＝ （ 3）0211)1(4 2nnnn且 222n 跟踪训练： 一、填空题： 方程组 3212 xxyxy 的解是。 方程组
如果实验中所用的滑动变阻器如图乙所示，你认为造成上述现象的原因是将滑动变阻器的 （ 用字母表示）两接线柱连入到电路引起的。 ②正确连接后，小金通过实验得到数据如下表，请分析数据并回答： 小灯泡的额定功率为 W。 依据表中的数据，可知滑动变阻器的最大阻值至少是 Ω （ 2）小丽使用的小灯泡额定电压为 伏。 根据电路图正确连接电路后，调节滑动变阻器滑片过程中，小灯泡的灯丝突然烧断了
如果 电压表的量程为 0~3V，求该装置所能测量的最大风力 电学热学综合题 15.(20xx 贵阳市 )在一次课外活动中，小悦同学对家用电磁炉进行了相关的观察和研究，并记录了电磁炉及她家电能表的有关数据，如下表：请你根据小悦同学在活动中获得的有关资料，求借在这段时间内 观察对象 有关记录 研究活动 电磁炉的铭牌 U 额 =220V P 额 =1kw ①用电磁炉加热一壶水 (水的质量为 2kg