lǎo / shī / ná / qǐ / kuò / yīn / qì / zài / cāo / chǎng / shàng / xuān / bù / le / bǐ / sài / guī / zé老师拿起扩音器,在操场上宣布了比赛规则。The teacher picked up a loudspeaker and announced the rules of the competition on the sports field.