A:I'm reading in the living room.
B:He's sleeping in the bedroom.
C:She's washing her hair in the bathroom.
Many students are afraid ____ (take) an English exam.
— my ruler?
— It's on the desk.
我国古代北方农民南迁,其主要原因是( )
两栖动物的成体用____呼吸,____辅助呼吸.
与圆x2+y2+2x=0及圆x2+y2-8x+12=0都外切的圆的圆心在 ( )