We have been excavating layers of ash almost six metres thick, which suggests that they________the fire burning all winter.
According to the arrangement, the athletes of our school ________ at the gym for two hours every day.
Our government's plan to fight against air pollution will focus on ________ information and handling PM2.5.
In fact fuels we burn and plant food we eat ________ their chemical energy in the form of heat.
Don't be so discouraged.If you ________ such feelings, you will do better next time.
Schools in China are required to ________ at least one “Sports Day” per academic year.