Some firms expect the guards to work twelve hours a day.

　　有些公司要求保安每天工作12小時。

　　Her own twelve pictures sold fairly well, mostly to friends and family.

　　她自己的12幅畫賣得相當好，多半賣給了朋友和家人。

　　A twelve hour night time curfew is in force.

　　正在執(zhí)行12小時的宵禁。

　　The building will house twelve boys and eight girls.

　　這座房子里會住12個男孩和8個女孩。