兴奋和抑制过程的灵活性,指对刺激的反应速度和兴奋与抑制相互转化替代的()。 A.频率 发布时间:2021-04-07 11:13 │ 来源:www.tikuol.com 题型:单项选择题 问题: 兴奋和抑制过程的灵活性,指对刺激的反应速度和兴奋与抑制相互转化替代的()。A.频率B.速度C.强度D.指向性
题型:单项选择题 阅读下面的短文,从四张图片中找出一个正确对象。 Hello. My name's Susan. I'm twelve years old. Look! This is a picture of my family. This is my mother and this is my father. This is my brother. His name is Simon. There is also my dog too. His name is Bobby. 1. 2. 3. 4. 查看答案
题型:单项选择题 观察下图,根据题意,回答下列问题:(1)若A是HIV,正在侵入B,则B最可能是_________细胞。(2)若B细胞内部已经侵入了麻风杆菌,正在与A接触,而且A最终导致B细胞裂解死亡,则A是_____细胞。(3)若A是B分泌出来的某种免疫球蛋白,则B的最初来源是__________细胞。(4)若A是病毒,它常作为基因工程的_____________,原因之一是具有标记基因;在动物细胞工程中可用作促进_________的诱导剂。 查看答案
题型:单项选择题 The police chief advised his men to keep________ and not lose their tempers.A.calmB.quietC.stillD.silent 查看答案