【多选题】下列关于对羟基苯甲酸酯的叙述,正确的有 ( )
【简答题】Harry Potter is a set of popular books created by J.K.Rowling in Britain. The books tell us some stories about a talented wizard (天才魔法师), Harry Potter. When he was eleven years old, he had an unhappy ...
【简答题】1- 10 室温下一高压釜内有常压的空气。为进行实验时确保安全,采用同样温度的纯氮进行置换,步骤如下向釜内通氮直到 4 倍于空气的压力,尔后将釜内混合气体排出直至恢复常压。这种步骤共重复三次。求釜内最后排气至年恢复常压时其中气体含氧的摩尔分数。设空气中氧、氮摩尔分数之比为 1 ∶ 4 。
【单选题】Harry Potter is the most interesting book ______ I have ever rea。
【单选题】-What do you think of the series of books Harry Potter? -Harry Potter is a world of magic and wonders,________ anything can happen.
【单选题】Harry Potter is the most interesting book ______ I have ever read。
【单选题】Harry Potter is so interesting a book that lots of teenagers like to read _