The days ____we spent together on the farm are not easy ______．
A.when,toforgetB.which, to be forgottenC.that, to forgetD./,to be forgotten在线课程C
解析：
第一空考查定语从句先行词The days关系词在从句中做宾语要用that\which\不填。第二空sth be easy to do 用主动结构表达被动含义。句意：我们一起在农场度过的日子不容易忘记。