根据Stocks方程计算所得的直径称为()
A. 定方向径
B. 等价径
C. 体积等价径
D. 有效径
E. 筛分径
Native Son is the masterpiece of______.
A. Ralph Ellison
B. Langston Hughes
C. Richard Wright
D. John Dos Passos
Not Without Laughter is written by______, the leading character of the Harlem Renaissance.
A. Langston Hughes
B. Richard Wright
C. Frederick Douglass
D. Alice Walker