单选题 The gray building is where the workers live, and the white one is where the spare parts ______.
A. are produced B. are producing
C. produced D. being produced

【正确答案】 A
【答案解析】[解析] 本题考查被动语态。spare parts(零件)与produce(生产)之间为被动关系，所以排除B、C项。这里不强调“正在被生产”，所以不选D。