一道语法题Bythetimeyougettoshanghaitomorrow,I_____forchongqing.
Bythetimeyougettoshanghaitomorrow,I_____forchongqing.
为什么选择shallhaveleft而不是选择willleave?
希望把知识点说详细是虚拟还是条件还是将来完成时.