The days we spend together on the farm are not easy .A. when; to forgetB. which; to be for

问题补充：

The days we spend together on the farm are not easy .

A. when; to forget

B. which; to be forgotten

C. that; to forget

D. /; to be forgotten

答案：

A. when; to forget

B. which; to be forgotten

(答案→)C. that; to forget

D. /; to be forgotten

解析：考查定语从句。第一个空要用关系代词引导定语从句修饰days，并作spent的宾语；第二个空放在easy后面要用不定式的主动形式。句意：我们在农场一起度过的日子永难忘记。故C正确。