第16题: [单项选择]What do we know about the man’s mother A. She is ill. B. She is a doctor. C. She came home yesterday. 参考答案:A 答案解析:[听力原文]
W: How is your mother feeling these days
M: Much better, thanks. The doctor said she could
第19题: [单项选择]用pH试纸测定某无色溶液的pH值时,规范的操作是:()。 A. 将pH试纸放入溶液中观察其颜色变化,跟标准比色卡比较 B. 将溶液倒在pH试纸上,跟标准比色卡比较 C. 用干燥的洁净玻璃棒蘸取溶液,滴在pH试纸上,跟标准比色卡比较 D. 在试管内放入少量溶液、煮沸。把pH试纸放在管口,观察颜色。跟标准比色卡比较 参考答案:C