零件各表面之间的实际位置与理想零件各表面之间位置的符合程度叫()。
参考答案:位置精度
阅读下面材料,在空白处填入适当的内容(1个单词)或括号内单词的正确形式。
Chengdu has dozens of new millionaires, Asia’s biggest building, and fancy new hotels. But for tourists like me, pandas are its top(61)(attract).
So it was a great honour to be invited backstage at the not-for-profit Panda Base, where ticket money helps pay for research, I(62)(arrow)to get up close to these cute animals at the 600-acre centre. From tomorrow, I will be their UK ambassador. The title will be(63)(official) given to me at a ceremony in London.But my connection with pandas goes back (64)my days on a TV show in the mid-1980s,(65)I was the first Western TV reporter(66)(permit) to film a special unit caring for pandas rescued from starvation in the wild. My ambassadorial duties will include(67)(introduce) British visitors to the 120-plus pandas at Chengdu and others at a research in the misty mountains of Bifengxia.
On mu recent visit, I help a lively three-month-old twin that had been rejected by(68)(it) mother. The nursery team switches him every few(69)(day) with his sister so that while one is being bottle-fed,(70)other is with mum-she never suspects.
69()
关于中心静脉压的叙述,错误的是()
A.指右心房和胸腔内大静脉的血压
B.正常变动范围为4~12cmH2O
C.是反映心血管功能的又一指标
D.心脏射血能力较强,中心静脉压就会较高
E.中心静脉压偏低,常提示输液量不足