如图所示,小球用不可伸长的长为L的轻绳悬于O点,小球在最低点的速度必需为多大时,才能在竖直平面内做完整个圆周运动?
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根据括号内的汉语提示,完成句子。
1. My ________ (第一的) name is Jack. What about yours?
2. Sorry, I can't ________ (拼写) the English word. Can you help me?
3. Mr. Smith has two ________ (女儿). They are both teachers.
4. Can you ________ (带来) some things to school, Ellen?
5. —Let's play soccer! —That ________ (听起来) great!
6. Tom ________ (观看) TV at home every day.
7. What ________ (食品) does your mother like?
8. I like ________ (草莓) very much. But she doesn't like them.
9. My family and I like ________ (运动) after dinner.
10. I don't like tennis. It's ________ (无聊的).
某鸡场4 周龄鸡出现咳嗽气喘、流鼻液症状。分泌物经0.45μm 滤膜过滤后接种牛心浸出液琼脂培养基,7 天后可见露珠状小菌落。该鸡群感染的病原可能是
A.鸡毒支原体
B.产气荚膜梭菌
C.多杀性巴氏杆菌
D.支气管败血波氏杆菌
E.产单核细胞李氏杆菌