推算
18=2×9
18=6×3
18=____×3
18=____×6
24=____×6
24=____×3
袁隆平院士利用野生水稻与普通栽培水稻多次杂交,培育出高产杂交水稻品种,这是利用了( )
—Is my clock on the table?
—No, _________. It's under the chair.