Điền từ
II Put the words into the THREE groups (/s/, /z/ and /iz/).
books, doors, windows, boards, clocks, bags, pencils, desks, schools, classrooms, students, teachers, couches, benches, glasses, brushes, maps, sinks, beds, calculators, villas, lamps <!--[if mso & !supportInlineShapes & supportFields]> SHAPE \* MERGEFORMAT <!--[endif]--><!--[if gte vml 1]--> <!--[if !mso]-->
<!--[endif]-->
books, doors, windows, boards, clocks, bags, pencils, desks, schools, classrooms, students, teachers, couches, benches, glasses, brushes, maps, sinks, beds, calculators, villas, lamps
<!--[if !mso]-->
<!--[endif]--><!--[endif]--><!--[if gte vml 1]--><!--[endif]--><!--[if mso & !supportInlineShapes & supportFields]--><!--[endif]-->
-/iz/: ......................................................................................................................................
-/s/: ......................................................................................................................................
-/z/: ......................................................................................................................................