By this time tomorrow we___the machine.A.have repaired B.shall have repaired C.will repair D.would repair

问题描述:

By this time tomorrow we___the machine.A.have repaired B.shall have repaired C.will repair D.would repair
为什么不选C,

因为是虚拟语气,而will不是虚拟语气词.
如果没有开头的那个by,就是C了