硫酸铜法测定比重时，挤下的血滴离硫酸铜溶液表面（）厘米以上滴入其中。
A.1
B.2
C.3
D.4
参考答案：A
As soon as little Tom had _______ a little from his shock, his first thought was to get away .[ ]
A. returned
B. benefited
C. survived
D. recovered
为防止雨水污染外墙墙身，应采取的构造措施称为（）
A、散水
B、踢脚
C、勒脚
D、墙裙
