1)shall,(我，我们)将要，会;必须，应该2)We must plant more trees,,我们必须多植树，3)We must discharge our functions.,我们必须尽责。4)We must set things going.,我们必须动起来。5)We must arm against the pestilence.,我们必须预防疫6)We must hold the contractors to (ie not allow them to exceed) their estimates.,我们必须使承包
