如图A、B所示分别为何种面瘫及两者区别。
参考答案：
A为中枢性面瘫B为周围性面瘫，中枢性面瘫为面神经核以上皮质脑干束病变，因为面上部肌肉接受双侧皮质核束的支配，一侧皮质核束的损害仅表现眼裂以下面瘫，出现患侧口角低垂、鼻唇沟变浅、鼓颊、露齿等动作不能，但肌肉不萎缩，亦无电反应变化，而周围性面瘫为面神经核或核发出的纤维病变表现为一侧全部面肌瘫痪，除面下部肌肉瘫痪的表现外，尚有患侧额纹变浅、皱额、闭目不能。
| Questions 81-90 are based on the following passage. 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. |
Researchers think that it is ______.
A．safe to eat fresh fish
B．dangerous to get close to the algae
C．safe to be near the algae
D．dangerous to expose the algae