40×(1-25)÷6
=24÷6,
=4(小时).
答:还要4小时耕完.
Lynn's mother is a nurse. She works in a .[ ]
A. shop
B. school
C. hospital
某有机物的结构简式为:,它在一定条件下可能发生的反应是
①加成;②水解;③酯化;④氧化;⑤中和; [ ]
A.①③④⑤
B.①②③④⑤
C.①③⑤
D.②③④⑤