在一个种群中,随机抽出一定数量的个体,其中基因型为BB的个体占14%,Bb个体占80%,bb个体占6%,则基因B的频率是[ ]
A.94%
B.54%
C.86%
D.17.2%
答案:B
许多影院的座位做成阶梯形,目的是______(请用数学知识回答).
He is ______ that he does everything very well.
A.so careful a student
B.so careful student
C.such careful a student
D.a such careful student