问题
选择题
—What did you do yesterday evening?
—I ________ with my friends. [ ]
A. watch TV
B. am playing
C. watched a football game
D. see a film
答案
答案:C
—What did you do yesterday evening?
—I ________ with my friends. [ ]
A. watch TV
B. am playing
C. watched a football game
D. see a film
答案:C
(6分)一定条件下,某物质溶解于水的实验数据如下表,请回答有关问题。
实验序号 | 温度/℃ | 水的质量/g | 所加物质质量/g | 溶液质量/g |
① | 20 | 10 | 2 | 12 |
② | 20 | 15 | 2.5 | a |
③ | 20 | 20 | 7 | 26 |
④ | 30 | 20 | 7 | 27 |
(2)20℃时,该物质的溶解度为 。
(3)右图中,能表示该物质溶解度的曲线是 (填字母)。
(4)所得溶液一定为饱和溶液的是 (填实验序号,下同); 所得溶液中溶质质量分数最大的是 。
(5)温度不变,将①、②所得溶液混合后,向其中再加入 g该物质,能使溶液恰好达到饱和。