- Is there a school near here?
-
A:Yes, it is.
B:No, there aren't.
C:Yes, there is.
判断对错.
正方形的周长是它的边长的4倍.
“日出江花红胜火,春来江水绿如蓝。”江水泛绿是由于下列哪类植物大量繁殖引起的
— Did you study any other languages English when you were at college?
— Yes, I studied three. But I have forgotten all a few words of each.
高等生物的生殖发育周期如图所示,请据图回答:
(1)生物的个体发育是从____ 开始的,主要进行____ 分裂.
(2)个体发育成熟后通过____ ____ 产生配子,它发生在植物的____ (结构)中,动物的____ (器官)中.
(3)图中B过程叫做____.
(4)青蛙的C____ 过程和D____ 过程合称为____ .
(5)高等动物胚胎发育的过程是:受精卵→卵裂→____ 胚→____ 胚(具有____ 个胚层)→____ .
(6)蛙的胚后发育属于____ .