A:闻大王有意督过之,脱身独去,已至军矣项王军在鸿门下,沛公军在霸上,相去四十里
B:沛公则置车骑项王则受璧,置之坐上
C:大行不顾细谨,大礼不辞小让臣死且不避,卮酒安足辞
D:先破秦入咸阳者王之
用如图所示的实验装置可以研究( )
-5+(-9)=____
—I think teenagers should be allowed to make their own decisions when they have problems at school.
—_______. They're not calm enough, after all.
小麦的毛颖(R)对光颖(r)为显性,抗锈(E)对感锈(e)为显性,这两对基因自由组合.用光颖感锈和毛颖抗锈的纯种小麦杂交,如果希望得到250株光颖抗锈纯种植株,那么F2代理论上要有多少株?( )