【单选题】读句子选择合适的答案填入括号中 Дети_________________________
【单选题】Oh, dear! I've lost my new watch. _____
【单选题】听力原文:W: Hi, Honey. I'm sorry, I've some bad news to tell you. The management is making cuts, and I've lost my job. M: Oh, dear! That's terrible. But you didn't like that job very much anyway. Maybe th...
A.
The woman shouldn't lose her job.
B.
The woman shouldn't be frustrated.
C.
The woman won't be laid off by the management.
D.
The woman can easily find new thing.
【单选题】已知邻苯二甲酸氢钾(KHC8H 4 O 4 )的摩尔质量为204.2g/mol,用它来标定0.1mol/LNaOH溶液,称取邻苯二甲酸氢钾为:()。
【单选题】已知邻苯二甲酸氢钾(KHC8H 4 O 4 )的摩尔质量为204.2g/mol,用它来标定0.1mol/LNaOH溶液,宜称取邻苯二甲酸氢钾为:()
【简答题】实验室常用邻苯二甲酸氢钾(KHC 8 H 4 O 4 )来标定氢氧化钠溶液的浓度,反应如下: KHC 8 H 4 O 4 +NaOH=KNaC 8 H 4 O 4 +H 2 O。邻苯二甲酸氢钾溶液呈酸性,滴定到达终点时,溶液的pH约为9.1。 (1)为标定NaOH溶液的浓度,准确称取一定质量的邻苯二甲酸氢钾(KHC 8 H 4 O 4 )加入250mL锥形瓶中,加入适量蒸馏水溶解,应选用_____...
【单选题】如今,路边很难再见到传统爆米花的售卖了,取而代之的是我们在电影院里常见的新式爆米花。那么,这两种爆米花有什么区别?哪种更健康呢?传统的爆米花是以玉米为原料,在小转炉中经过高温加热后制成,其中可能添加了一些糖精来调味,但不会加入任何人造黄油类的脂肪。传统爆米花虽然脂肪含量不高,但传统的小转炉在高温下可能会释放出铅。而现在电影院的食售柜台都用电器烘烤爆米花,在制作过程中往往会加入大量的人造奶油、香精和...