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【多选题】
下列对体系与环境的表述中正确的有( )A.
体系与环境一定没有关系
B.
体系与环境一定有相互作用
C.
体系与环境之间不一定有明显边界
D.
体系是一种人为的划分
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举一反三
【单选题】Which group of people are not mentioned about falling suicide rates?
A.
middle-aged men in the US
B.
young women in China
C.
old people in the world
D.
young women in India
【单选题】下列关于键和键槽错误的叙述是 :
A.
钩头楔键的上、下底面是工作面，两侧面是非工作面，所以画楔键连接图时，键的两侧面与轴键槽和轮毂键槽侧面间应留有间隙；
B.
平键的两侧面是工作面，上、下底面是非工作面，所以画平键连接图时，上底面与轮毂键槽顶面之间应留有一定间隙；
C.
一般用移出断面图或局部视图表达平键键槽的结构和尺寸，在这类图中应直接标出键槽的深度 t 或 t1
D.
根据轴径就可在相关国标中查出键和键槽的相关尺寸。
【单选题】Nominal interest rates tend to be higher in countries with
A.
higher rates of inflation
B.
lower rates of inflation
C.
lower real interest rates
D.
Both B and C
【单选题】What's the main sentence? Life without an externally supported daily plan can lead to higher rates of drug abuse, crime, suicide.
A.
A daily plan can lead to higher rates.
B.
Life can lead to higher rates.
C.
Life supported a daily plan.
D.
A daily plan can lead to drug abuse, crime, suicide.
【单选题】While shocks of life tend to cause increases in the rates of many diseases, social contacts can help us to get through these otherwise very rough changes.
A.
Y
B.
N
C.
NG
【单选题】Unemployment rates tend to:
A.
be the same across geographic areas.
B.
vary between age groups and ethnicities.
C.
increase when the economy expands.
D.
stay the same only when there is cyclical unemployment.
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