问题
单项选择题 A1/A2型题
正常情况下,脐带中的静脉条数是()
A.5条
B.4条
C.3条
D.2条
E.1条
答案
参考答案:E
解析:脐带是连接胎儿与胎盘的带状器官,内有一条管腔较大、管壁较薄的脐静脉和两条管腔较小、管壁较厚的脐动脉。
正常情况下,脐带中的静脉条数是()
A.5条
B.4条
C.3条
D.2条
E.1条
参考答案:E
解析:脐带是连接胎儿与胎盘的带状器官,内有一条管腔较大、管壁较薄的脐静脉和两条管腔较小、管壁较厚的脐动脉。
阅读理解。 | |||
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1. When people come to visit the Gallery, they should ______. | |||
A. leave all their carried items at the checkrooms B. have all their carried items x-rayed at the entrance C. take all their carried items with them without inspection D. have all their carried items inspected at the entrance | |||
2. What does the Gallery feel sorry for? | |||
A. Visitors have to keep their valuable items in the checkrooms. B. The size of visitor items allowed into the Gallery is limited. C. It cannot keep oversized visitor items due to limited space. D. Visitor items over 17×26 inches must go through additional checks. | |||
3. Parents with small children visiting the Gallery ______. | |||
A. can carry their children in soft front child carriers B. can carry their children on their shoulders C. can carry their children in child carriers worn on the back D. ought to pay if they want to use pushchairs for their children | |||
4. Visiting photographers should make sure that ______. | |||
A. pictures and videos are allowed for personal use anywhere in the Gallery B. pictures and videos can be taken in some places for personal use C. picture-taking and videoing are totally forbidden in the Gallery D. tripods are allowed except in some special exhibitions |