为使钻井仪表起防爆作用,内部需予充0.5~1PSI之间压力的()。A、氧气B、氮气C 发布时间:2017-08-06 00:39 │ 来源:www.tikuol.com 题型:单项选择题 问题: 为使钻井仪表起防爆作用,内部需予充0.5~1PSI之间压力的()。A、氧气B、氮气C、氢气D、氨气
题型:单项选择题 Tomorrow is Saturday. It is Linda, my 1 birthday. She will 2 seven years old. She is very happy because she 3 to school in autumn. We are all very 4 , too. We are going to 5 a party for her. My mother will make her a big _6 __. She likes reading ,my father will buy her an interesting 7 _. I will buy a CD _8 her ,9 she likes singing. She is going to 10 her favorite songs for us. We all hope she can be happy forever (永远).小题1:A.father’sB.mother’s C.sister’sD.brother’s小题2:A.beB.isC.areD./小题3:A.goingB.goC.goesD.will go小题4:A.sadB.niceC.happyD.cool小题5:A.giveB.haveC.makeD.use小题6:A.photoB.planC.cakeD.picture小题7:A.scienceB.storybookC.computerD.bike小题8:A.toB.ofC.fromD.for小题9:A.becauseB.butC.andD.or小题10:A.writeB.singC.showD.give 查看答案
题型:单项选择题 富兰克林是根据带电体间的相互作用,发现电荷有正、负两种,如图所示,绝缘细线上端固定,下端悬挂一轻质小球a,a的表面镀有铝膜,在a的近旁有一固定绝缘金属球b,则( )A.若a顺时针摆动,证明a、b带同种电荷B.若a逆时针摆动,证明a、b带异种电荷C.若a顺时针摆动,证明a、b带异种电荷D.若a逆时针摆动,证明a、b带同种电荷 查看答案