① 检查滴定管是否漏水;② 用蒸馏水洗涤玻璃仪器;③ 用标准溶液润洗盛装标准溶液的滴定管,用待测液润洗盛待测液的滴定管;④ 装标准溶液和待测液并调整液面(记录初读数);⑤ 取一定体积的待测液于锥形瓶中;⑥ 滴定操作
A:①③②④⑤⑥
B:①②③④⑤⑥
C:②③①④⑤⑥
D:④⑤①②③⑥
已知α与β是钝角,甲、乙、丙、丁四个人计算16(α+β)的结果依次为28°,48°,60°,88°其中只有一个结果正确,那么并得到正确的结果的是( )
小岳的爸爸从印度考察回来,想考考他的地理知识,故意说错了一项,请你帮小岳找出来( )
已知曲线y=x4+ax2+1在点(﹣1,a+2)处切线的斜率为8,a=( )
阅读下面的内容,并对后面的句子作出判断。
It isn't a small shop(商店). It is near our home. It looks very lovely. My parents and I often go shopping. I buy books, rulers and pens in the shop. My parents buy milk , bread and eggs. The service(服务) is very good. We all like the shop.