A. They are very sensitive to surrounding stimuli. B. They are almost useless. C. They require group cooperation. D. They are similar to those of most sea creatures. 参考答案:A 答案解析:根据最后一段可知海参在受到外界刺激时,会做出一定的反应,这也反映出它的防御机制非常敏感,故A为正确答案。
第27题: [单项选择]下列哪项情况不能说明病人有产褥感染() A. 产后3天,会阴伤口红肿,有脓性分泌物 B. 产后5天,持续低热,恶露增多有臭味,下腹疼痛,有压痛感 C. 产后7天,宫底脐下2指 D. 产后1天,宫缩痛,哺乳时疼痛明显 E. 产后9天,出现弛张热,下肢持续性疼痛,伴水肿,皮肤发白 参考答案:D