豌豆从播种到收获为1年时间,纯种高茎豌豆与纯种矮茎豌豆杂交得F1种子,F1自交产生的F2中高茎和矮茎的比例为3:1。纯种黄色圆粒豌豆与纯种绿色皱粒豌豆杂交得F1,F1自交得F2中各种表现型的比例为9:3:3:1。上述实验分别需要在第几年才能得出结果( )
_______do you watch TV?
Twice a week.( )
A.How oftenB.How longC.How soon
Where is Jim?
Look! He _______ under the tree.( )
A.is standingB.stood
C.stands
My daughter is years old. Today is her birthday.( )
A.nine; ninethB.nine; ninth
C.ninth; nine
Is this your English book?
No, it's my brother's. is over there.( )
A.MineB.MyC.Me
My grandfather does Chinese Kung Fu every day _________ he is over eighty. ( )
A.sinceB.thoughC.until