孔内扩散系数根据气体分子平均自由程与孔径的相对大小进行划分。
查看答案
努森扩散系数与压力成正比，与孔径成反比。
A. 对
B. 错
Xi'an is ___ old city with ___ long history, isn't it?
A. a, an
B. an, a
C. the, the
D. the, a
More college graduates would like to work in _______ west part of our country ______ next year.
A. the, the
B. /,/
C. /, the
D. the, /
Chaffs is______ boy, but he can play the guitar very well.
A. an eight-years old
B. a eight-year-old
C. a eight-years-old
D. an eight-year-old
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