两对相对性状的基因自由组合,如果F2的分离比分别为9:7、9:6:1和15:1,那么F1与双隐性个体测交,得到的表现型分离比分别是
Last week, he Beijing with his family A. go to B. goes to C. went to
What you last weekend? A. do ; do B. did ; did C did ; do
Where Su Hai and her mother last weekend? A. was B. is C. were
Long long ago, an old woman on the moutain.
He is hard.But he still can’t get the answer.