【简答题】面筋具有延伸性、弹性、可塑性和( )等性质。
【简答题】东部市场( )有需求量并可以成交,中部市场( )有需求量并可以成交,北部市场( )有需求量并可以从成交,西部市场( )有需求量 并可以成交。
【单选题】某城市 E 和 ESE 风向出现的频率分别为 20% 和 18% ,静风频率为 45% ,新建热电厂选址方案正确的是( )。
【简答题】完形填空。 Scott and his companions were terribly disappointed. When they got to the South Pole, they found the Norwegians (挪威人)had 1 them in the race to be the first ever to reach it. After 2 the British ...
【简答题】Scott and his companions were terribly disappointed. When they got to the South Pole, they found the Norwegians(挪威人)had 36 them in the race to be the first ever to reach it. After 37 the British...
【单选题】When they got to the cinema, the play ______ for half an hour.
【简答题】增塑剂(又叫塑化剂)是一种增加塑料柔韧性、弹性等的添加剂,不能用于食品、酒类等行业。DBP(邻苯二甲酸二丁酯)是增塑剂的一种,可由下列路线合成: 已知以下信息: ① ② (-R 1 、-R 2 表示氢原子或烃基) (1)A的结构简式 ,D→E的反应类型 。 (2)DBP的分子式为 ,D的结构简式是 。 (3)由B和E以物质的量比1︰2合成DBP的化学方程式: 。 (4)写出同时符合下列条件的B的所...