协调环(相依环)是根据装配精度指标确定组成环公差。()
装配尺寸链中的封闭环存在于零部件之间，而绝对不在零件上。()
The chronic fiscal deficit of the U.S. is due to
A. increasing federal programs.
B. expenses for the aged and the disabled.
C. increased health care costs.
D. insufficient federal taxation.
We can conclude from paragraph 2 that
A. Government spending and taxation have nothing to do with people"s livelihood.
B. Political and economic policies has a negative impact on some American"s livelihood.
C. tax and spending policies plays a very important role in reducing debts.
D. increasing private investment spending and export can boost economy.
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