问题
选择题
His sister likes _____________ the swings.
A. playing on
B. plays on
C. playing at
答案
答案：A
搜题请搜索小程序“爱下问搜题”
His sister likes _____________ the swings.
A. playing on
B. plays on
C. playing at
答案：A
除去下列各物质中的少量杂质．所选用的试剂及操作方法均正确的是
| 物质 | 杂质 | 除杂所用的试剂和方法 | |
| A | CaO固体 | CaCO3固体 | 加入水，过滤 |
| B | Fe | Cu | 加入适量的稀盐酸，过滤 |
| C | CO2气体 | 水蒸气 | 通过盛有氢氧化钠固体的干燥管 |
| D | NaCl溶液 | NaOH | 加入适量的稀盐酸 |