zhì / zuò / hùn / níng / tǔ / shí / xū / yào / xiān / bǎ / shuǐ / ní / hé / shā / zi / bàn / huò / zài / yì / qǐ制作混凝土时,需要先把水泥和沙子拌和在一起。When making concrete, you first need to blend the cement and sand together.