only when they_ the importance of the plan,will they make up their minds to carry it on.
问题描述：
only when they_ the importance of the plan,will they make up their minds to carry it on.
have realized为什么用现在完成式呢
答
只有当他们意识到这个计划的重要性,他们才会下定决心去继续做这个计划.
根据意思,这个“意识到”是要已经意识到,才会下定决心去继续做这个计划.
现在完成时强调对现在的影响,意思到重要性对现在的影响就是才会那样去做啥.