题目

Most animals have little connection with animals of adifferent kind unless they hunt them for food. Sometimes, however, two kindsof animals come together in a partnership which does good to both of them.You may have noticed some birds sitting on the backs of sheep. This is notbecause they want a ride, but because they find easy food in the parasites(寄生虫) on sheep. The sheep allow the birds todo so because they remove the cause of discomfort. So although theycan manage without each other, they do better together.     Sometimes an animal has a plant partner. Therelationship develops unt如图为生物膜结构模式图，a、b表示两种物质，下列叙述正确的是（　　） A、若该图表示质膜，则膜两侧还应分布有多糖B、若b表示O2，则该膜可能为叶绿体内膜C、若该图表示粗面内质网膜，则b可能是磷脂D、若a表示ADP，则该膜可能为蓝细菌质膜