A:came; would have come
B:had come; would have come
C:would have come; had come
D:would come; had come
澳大利亚的科学家巴里.马歇尔和罗宾.沃伦,发现了幽门螺杆菌是引起胃炎和胃溃疡等疾病的病原体,从而获得了2005年诺贝尔医学奖.从细胞结构看,幽门螺杆菌与植物细胞的主要区别是( )