下面哪项不是门脉高压的侧支循环路径（）。 A.脾静脉 B.副脐静脉 C.胃冠状静脉 发布时间：2017-05-10 20:57 │ 来源：www.tikuol.com 题型：单项选择题 问题： 下面哪项不是门脉高压的侧支循环路径（）。A.脾静脉B.副脐静脉C.胃冠状静脉D.肠系膜静脉E.内乳静脉
题型：单项选择题 请你说一说：风还能帮人们做哪些好事？风还有哪些危害？__________________________________________________________________ 查看答案
题型：单项选择题 It sounds like a science fiction, but researchers say it’s a scientific fact: Microscopic organisms dubbed "killer algae" are paralyzing fish with unknown toxins and then eating away at their flesh. They might be making people sick, too. The name given to this single-cell organism, or dinoflagellate, is Pfiesteria piscimorte—literally, "fish killer." It was discovered at North Carolina State University in 1988, but at the same time, few scientists believed in its existence, much less in its highly unusual predatory nature. But ongoing research has led to international acknowledgment of the phenomenon and, recently, research funding. Seemingly prompted by an unknown substance secreted by fish, the aggressive creature swims into action. It sends neurotoxins into the water and air, paralyzing a fish’s nervous system, and causing it to gasp for air at the surface. Eventually the fish suffocates. The killer dinoflagellate then attaches itself to the fish and begins sucking away at its flesh. This macabre scenario may help solve several sea mysteries, such as why fishermen report seeing "fish walks" (fish trying to leave the water) and pools of dead fish with holes eaten through them. Whether humans are affected by the dinoflagellate’s toxin remains to be seen. Researchers think it’s unlikely eating fresh fish are in danger, but anyone with frequent exposure to the creature could be in peril. Several researchers working with the algae have reported bouts of memory loss and disorientation. To understand the killer algae further, scientists must fully characterize their toxin and determine what stimulates them to attack. They also need to know if the algae are hurting fish populations, and whether pollutants make them more likely to attack.The word "they" underlined in Paragraph 1 refers to ______ .A．organismsB．fishC．toxinsD．flesh 查看答案