玉米属于雌雄同株异花植物,雄穗着生于植株顶端,雌穗位于茎秆中部叶腋间。隐性突变b基因纯合使植株不出现雌穗而变成雄株,隐性突变t基因纯合会使原来产生花粉的雄穗变成雌穗面转变成雌株。若要后代只获得雄株和雌株,则最佳的杂交组合是:
Could you take out the rubbish and do the dishes,Tony?
Sure,Mom will be mad if she sees this _________,I think.( )
A.matterB.messC.troubleD.difficulty
Would you help us make a plan to explore Tibet?
___________.( )
A.No,thanks.
B.Yes,of course.
C.It's very kind of you.
Does he need _____ there at once?
No,he _______ leave so hurriedly because he has enough time.( )
A.to go; doesn't needB.go; needn't
C.to go; needn't
Where is your father?
I don't know,but he _______ the car when I left just now.( )
A.is washingB.washed
C.was washing
The _______ show on Zhejiang TV,Running Men,makes lots of people _______.( )
A.interesting; relaxing
B.interesting; relaxed
C.interested; relaxed