【简答题】完形填空。 Once, in a small village, lived a family with eight children. Two of the children loved 1 very much, but the family was so poor that it was impossible to send 2 of them to study at the art colle...
【单选题】The children loved their day trip, and they enjoyed the horse ride .
【单选题】磁航向 315 ° ADF 指示相对方位角 140 °,飞机磁方位角为 。
【简答题】通常按照植物对光照度的适应程度将其划分为三种类型 、 、 。
【单选题】假设a、B为玉米的优良基因,现有AABB、aabb两个品种,控制两对相对性状的基因位于两对同源染色体上,实验小组用不同方法进行了实验(见下图),下列说法不正确的是 [ ]
A.
过程①育种方法的原理是基因突变,最大优点是能提高突变率,在短时间内获得更多的优良变异类型
B.
过程②③④育种方法的原理是基因重组,基因型aaB_的类型自交后,子代中aaBB所占比例是5/6
C.
过程⑤常使用的试剂是秋水仙素,它可作用于正在分裂的细胞,抑制纺锤体的形成
D.
过程⑥⑦应用了单倍体育种的方法,最大的优点是明显缩短育种年限
【多选题】Drugs may accumulate in various areas of the body as a result of ( )
D.
active transport into cells
【简答题】通常按照植物对光照度的适应程度将其划分为__、__、__。按顺序哦
【简答题】Today we tell about Louisa May Alcott. She wrote one of America ’s best loved children’s books . In 1868, an American publisher asked Louisa May Alcott to write a book for girls. At first, she was not...