1.答案：C.
2.翻译：布莱克先生叫人修理过的的电脑又坏了,这使得他很生气.
3.
1）该句中the computer是主语,主干是The computer was out of order again.
而Mr.Black had ___ 是定语从句,修饰先行词the computer.
2) 关系代词which/that代替先行词the computer,在定语从句中充当动词had的宾语,所以关系代词被省略了.
3）定语从句Mr.Black had (which/that=the computer) repaired中含有一个固定的结构：“使役动词have + 宾语(which/that=the computer) + 宾语补足语repaired”,意思是“使/让它(电脑)被(他人)修理”.