一产妇为恢复体形，最佳体操锻炼时间为
A．产后42周
B．产后12周
C．产后1个月
D．产后24周
E．产后1周
参考答案：D
--What on earth are the police busy with?
---They have been looking into how the plane crash _______.
A．came out
B．came up
C．came down
D．came about
花卉施肥应掌握（）原则。
A、薄肥少施
B、浓肥勤施
C、浓肥少施
D、薄肥勤施
