How would you deal with the problem? How about asking our teacher for help?
A:mind
B:solve
C:expect
如图,下列条件中:①∠B+∠BCD=180°;②∠1=∠2;③∠3=∠4;④∠B=∠5,能判定AB∥CD的条件为( )
假定五对等位基因自由组合,则杂交组合AaBBCcDDEe×AaBbCCddEe产生的子代中,有一对等位基因杂合、四对等位基因纯合的个体所占的比率是( )
在△ABC中,角A,B,C的对边分别为a,b,c,ac=3,且a=3bsinA,则△ABC 的面积等于( )