问题
选择题
The doctor worked ___ five hours ___ a rest. [ ]
A. for; with
B. on; without
C. about; having
D. for; without
答案
答案:D
The doctor worked ___ five hours ___ a rest. [ ]
A. for; with
B. on; without
C. about; having
D. for; without
答案:D
下表四组实验中“操作及现象”与“溶液”对应关系错误的是
选项 | 溶液 | 操作及现象 |
A | BaCl2溶液 | 通入SO2,无明显现象。再通入Cl2,溶液变浑浊。 |
B | BaCl2溶液 | 通入SO2,无明显现象。再通入NH3,溶液变浑浊。 |
C | Ca(ClO) 2溶液 | 通入过量CO2,溶液变浑浊。再加入品红溶液,红色褪去。 |
D | Na[Al(OH)4]溶液 | 通入过量CO2,溶液变浑浊。再加入过量盐酸,浑浊消失,且有气泡产生。 |