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【多选题】
下列关于形心惯性主轴的提法中, 是 错误的 .A.
任何平面图形都存在着两根相互垂直的形心惯性主轴
B.
任何平面图形的两根形心惯性主轴都必然是相互垂直的
C.
任何平面图形有两条形心惯性主轴
D.
如果已知平面图形 P 有三条形心惯性主轴，那么任何过 P 形心的直线都是 P 的形心惯性主轴
E.
如果已知平面图形 P 关于直线 l 对称，那么 l 必定是 P 的一根形心惯性主轴
F.
如果已知平面图形 P 关于直线 l 对称，那么垂直于 l 且心的直线必定是 P 的另一条形心惯性主轴
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【单选题】利用水准仪测量隧道洞顶水准点高程时，已知拱顶点高程为35m，若已知点水准尺读数为1.515m，待测点水准尺读数为2.015m，则待测点高程为（）
A.
35.500
B.
34.500
【单选题】利用水准仪测量隧道洞顶水准点高程时，已知拱顶点高程为35m，若已知点水准尺读数为1.515m，隧道地面上待测点水准尺读数为2.015m，则待测点高程为()
A.
31.470
B.
34.500
【单选题】Why did Dr．Baum come to a British national park?
A.
Because he needed to present it with a council’s diploma．
B.
Because he was concerned about its management．
C.
Because it was the only national park of its kind in Europe．
D.
Because it had never before received a diploma from the Council
【单选题】Under the National Health Service, British citizens ______.
A.
are all registered with a general practitioner
B.
do not need to buy private health insurance
C.
can only go to see a general practitioner
D.
cannot call in a general practitioner
【单选题】Dr. Baum, a representative of the Council, visited one particular British national park because _______.
A.
he was presenting the park with a diploma for its achievements
B.
he was concerned about how the park was being run
C.
it was the only national park of its kind in Europe
D.
it was the only park which had ever received a diploma from the Council
【单选题】利用水准仪测量隧道洞顶水准点高程时，已知地面点高程为35m，若已知点水准尺读数为1.515m，待测点水准尺读数为2.015m，则待测点高程为（）
A.
34.500
B.
38.530
【简答题】The British national anthem is _____ _____ _____ _____
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