题目

A good teacher always leaves his students enough time to think and voice their opinions in class, ______ he may not complete his teaching task.     A. in case            B. even if            C. as long as        D. as if   答案：B下列不属于细胞间信息交流实例的是 [     ]A．垂体分泌的促甲状腺激素通过血液运输到甲状腺，与甲状腺细胞膜表面的受体结合B．吞噬细胞对抗原处理后，以直接接触方式将抗原呈递给T细胞C．高等植物细胞之间通过胞间连丝进行物质运输和信息交流D．细胞内通过蛋白质纤维组成的网架结构进行物质运输、能量转换和信息传递