画出图中加在杠杆上的动力F的力臂.
如图所示
Have you ever dreamed of __________ such a good chance for further education abroad?
A.there is
B.there to be
C.there will be
D.there being
《传染病防治法实施办法》明确规定,应由国家卫生行政部门指定的保藏管理单位供应()类菌(毒)种。
A.一类
B.二类
C.三类
D.一类和二类