Anyvisitorstotheproductionfacilitiesmust____asecuritypassfromtheinformationdeskatthefrontentrance.
All_____fortimeoffmustgothroughtheHumanResourcesDepartmentfirst.
Itisestimatedthat，currently,about50，000speciesbecome_____everyyear．
下列关于1935年《中华民国刑法》的表述，正确的有
设函数y=sinx^2+2x，求dy
