be to
01
将要, 预计
used for expressing possibility or for indicating something that is due to happen or take place
例子
If we are to win this game, we must play our best.
如果我们要赢得这场比赛，我们必须发挥出最好的水平。
1.1
必须, 应该
used to express necessity or obligation
例子
All employees are to wear identification badges while on company premises.
所有员工在公司场所内必须佩戴身份徽章。
