He found he had not brought money with him when he was about to pay the b___
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Mrs. Johnson takes pride _____ her daughter, who came first in the race.
A. in
B. by
C. of
D. off
Thanks ___ our medical knowlege, this terrible disease is much less common now.
A. in
B. to
C. from
D. at
You cna pick _____ some useful ideas through talking with your teachers.
A. to
B. at
C. out
D. up
在临床疗效的研究中,下列哪种试验方案最可靠并且最常用:()
A. 随机对照试验
B. 非随机对照研究
C. 交叉对照试验
D. 历史性对照试验
E. 序贯试验