A.方孔篩篩孔大; B.圓孔篩篩孔大; C.兩者一樣大
A.至少15kg; B.至少7.5kg; C.至少3.75kg; D.至少30kg
A.50mm有孔篩; B.25mm方孔篩; C.25mm圓孔篩; D.13mm方孔篩