《耒耜经》记载:“进之则箭下,入土也深;退之则箭上,入土也浅。……江东之田器尽于是。”材料所描述的农具是下面的
答案:D
There are eight tips in Dr.Roger's lecture on sleep,and one of them is:________ to bed early unless you think it is necessary.
A.doesn't go
B.not to go
C.not going
D.don't go
网络组巡维护工作包括()
A.基础管理情况
B.设备运行情况
C.实际操作技能
D.解决问题情况