题目

小明要配制50g质量分数为14%的氢氧化钠溶液制作“叶脉书签”，下列关于配制该溶液的说法不正确的是（ ） ①若用氢氧化钠固体配制，需称取氢氧化钠固体7.0g ②用托盘天平称氢氧化钠固体时，在两盘各放一张质量相等的纸 ③选用200ml量筒量取所需水的体积 ④实验中用到的玻璃仪器有烧杯、量筒、玻璃棒和试剂瓶 ⑤用量筒量取水时，俯视读数，配得溶液的溶质质量分数偏小． A．①③ B．②③⑤   C．③⑤ D．②④⑤Joker found one of the biggest diamonds in the world right in his own back yard. He sold the stone to a diamond dealer for over three hundred thousand dollars. In New York, the diamond was resold---this time for almost eight hundred thousand dollars. The true value of a diamond is never known until it has been cut. Once cut successfully, its value can increase a thousand times. It's easy to understand why the owner of Joker's diamond went to the best diamond cutter he knew, Kaplan. The cutter studied the diamond for twelve whole months.When he felt he was ready to start work, he discovered a flaw (瑕疵) . He had to begin his calculations all over again, or he might have made the stone useless. Six months passed, and Kaplan finally said to the owner, “I am ready to start my work. There will be one excellent diamond that will be comparable one excellent diamond of first-class quality (质量)  " Kaplan waited a few more days until he felt he was in the best physical and mental (精神的) condition(条件) possible. He picked up his tools (工具) and held his breath as he made the diamond exactly as he promised.小题1:Joker found one of the biggest diamonds in the world_________.A．in a minuteB．at the foot of a big mountainC．in his own back yardD．in a garage (汽车库)小题2:A diamond dealer is a person ___________.A．in the diamond businessB．who stole diamondsC．who cuts diamondsD．who sells diamonds小题3:When the diamond was resold,____________.A．the dealer lost a lot of moneyB．Joker made some more moneyC．the dealer got 800, 000 dollarsD．Kaplan got 800,000 dollars小题4:The owner of the diamond thought that if the diamond was cut successfully it might be worth_________.A．$ 300, 000B．$ 500,000C．$ 300, 000D．$ 800,000,000小题5:Kaplan studied the diamond for____________.A．more than one and a half yearsB．more than half a yearC．over eight months D．more than nineteen months