onDblClick是指（）触发事件。
A.鼠标单击时
B.鼠标双击时
C.鼠标经过时
D.鼠标移开时
参考答案：B
Why are you still doing it? You should ______ it earlier. [ ]
A. have finished
B. not finish
C. finish
D. haven't finished
野外鉴别土壤质地采用的是（）。
