gōng / chéng / shí / shì / bīng / yòng / shí / nǔ / bǎ / jù / shí / shè / xiàng / chéng / qiáng攻城时,士兵用石弩把巨石射向城墙。During the siege, the soldiers used a stone catapult to hurl large rocks at the city wall.