Passage One Questions 26 to 29 are based on the passage you have just heard.
A. Market investigation and sales promotion are closely related.
B. It is impossible to succeed in selling a product without market investigation.
C. There are various ways of making market investigation.
D. Production goes before market investigation.
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Ni晶体的错排间距为2000nm,假设每一个错排都是由一个额外的(110)原子面所产生的,计算其小倾角晶界的θ角。
有两根左螺旋位错线,各自的能量都为E1,当它们无限靠拢时,总能量为多少
Al的空位形成能(Ev)和间隙原子形成能(Ei)分别为0.76eV和3.0eV,求在室温(20℃)及500℃时,Al空位平衡浓度与间隙原子平衡浓度的比值。