this is the best place __I have ever visited all my lifeAwhich Bthat Cwhere Dwhen请讲明理由

this is the best place __I have ever visited all my lifeAwhich Bthat Cwhere Dwhen请讲明理由
this is the best place __I have ever visited all my life
Awhich Bthat Cwhere Dwhen请讲明理由

this is the best place __I have ever visited all my lifeAwhich Bthat Cwhere Dwhen请讲明理由
that 前面是best place 表示特指某一地点,因为最好的地方是独一无二的,所以只能用that,不能用where.
希望我的回答能对你有帮助
如果还有问题,可以问我,^_^

B
best 是最高级，后面的定语从句只能用that 做先行词