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• 12.一定条件下磷与干燥氯气反应，若0.25 g磷消耗掉314mL 氯气（标准状况），则产物中PCl3与PCl5的物质的量之比接近于(A) 3 : 1 (B) 5 : 3 (C) 2 : 3 (D)
• 18．一水平抛出的小球落到一倾角为的斜面上时，其速度方向与斜面垂直，运动轨迹如右图中虚线所示。小球在竖直方向下落的距离与在水平方向通过的距离之比为
• 10. He wondered if he could slip out of the lecture hall without anyone _________.(A) noticing
• 15. 某物体左右两侧各有一竖直放置的平面镜，两平面镜相互平行，物体距离左镜4m，右镜8m，如图所示，物体在左镜所成的像中从右向左数的第三个像与物体的距离是 　　(A)24m (B)32m (C)40
• 13.下面关于SiO2晶体网状结构的叙述正确的是(A).最小的环上，有3个Si原子和3个O原子(B)最小的环上，Si和O原子数之比为1：2(C)最小的环上，有6个Si原子和6个O原子(D)存在四面体结
• 2．甲、乙两种酶用同一种蛋白酶处理，酶活性与处理时间的关系如下图所示。 下列分析错误的是(A)．甲酶能够抗该种蛋白酶降解(B)．甲酶是不可能具有催化功能的RNA(C)．乙酶的化学本质为蛋白质(D)．乙
• 11. – You realize that you were driving at 100 miles per hour, don’t you?-- No, officer, I ____
• 9.下列叙述正确的是(A) 某醋酸溶液的PH＝ a，将此溶液稀释1倍后，溶液的PH＝ b，则a>b(B) 在滴有酚酞溶液的氨水中，加入NH4Cl的溶液恰好无色，则此时溶液的PH< 7(C)
• 19．右图为两分子系统的势能与两分子间距离的关系曲线。 下列说法正确的是　　(A)．当大于r1时，分子间的作用力表现为引力　　(B)．当小于r1时，分子间的作用力表现为斥力　　(C)．当等于r2时，分
• 14.原子核经放射性衰变①变为原子，继而经放射性衰变②变为原子核，再经放射性衰变③变为原子核。放射性衰变①、②和③依次为(A). 衰变、衷变和衰变 (B) 衰变、衷变和衰变(C) 衰变、衰变和衰变 (
• 12. Class is to begin in a minute, but the teacher still hasn’t _____.(A) come on (B) turned ou
• 3．番茄幼苗在缺镁的培养液中培养一段时间后，与对照组相比，其叶片光合作用强度下降，原因是(A)．光反应强度升高，暗反应强都降低(B)．光反应强度降低，暗反应强都降低(C)．反应强度不变，暗反应强都降低
• 13. By the end of last year we _____ more than 200 students of English all over the province.(A
• 4．取紫色洋葱外表皮，分为两份，假定两份外表皮细胞的大小、数目和生理状态一致，一份在完全营养液中浸泡一段时间，浸泡后的外表皮称为甲组；另一份在蒸馏水中浸泡相同的时间，浸泡后的外表皮称为乙组。然后，两组
• 6. He took the machine to pieces to find out how it _______.(A) progressed (B) operated (C) equ
• 14. ______ the teacher’s suggestion, Tom finally found a way to settle the problem.(A) Followin
• 7. I asked two people to help me start my car, but ____ of them knew what to do.(A) either (B)
• 15. – Hello, may I speak to Dr. Bush?--_________________.(A) Yes, I’m Bush (B) Yes, it’s me(C)
• 16. Of the two new teachers, who do you like______?(A) much (B) better (C) well (D) the most
• 17. Something about his manager suggested that he _____ not interested in what we were doing.(A
• 18. The belief that the children of working mothers usually suffer is_____ by most scientists.(
• 27. Have you ever been to the square ______ was built last year?(A) which (B) where (C) when (D
• 19. Catherine is one of the brightest students who _____ from the Department of Computer Scienc
• 28. They started off at about 5 o’clock in the morning. They should ____ there by now.(A) arriv
• 20. I always regret not _____ harder when I was young.(A) studying (B) having studied(C) to stu