下图表示人的受精及胚胎发育过程，请据图回答。

（1）A是____ ，它是由____ 产生的。
（2）B是____ ，C是____ 。
（3）D表示____ 过程。胎儿通过____ 和脐带从母体获得营养。

元朝是我国第一个统一全国的少数民族政权，下列事件发生在元朝的是（    ）

①铁木真统一蒙古  ②回族形成  ③编写《农桑辑要》  ④建立行省制度

   This is my beautiful home. There is a small garden in front of my house. There are many beautiful flowers in the garden. Behind my house there is a big tree. Near the tree, you can see a garage. My father’s beautiful car is in it now.
   On the first floor, there is a large living room, a dining room, a kitchen and a bathroom. I like watching TV in the living room. On the second floor, there is a small study room and two bedrooms. I love playing with the computer in my study. 
   What a nice home! I like it very much.

近日，上海、北京、广州等一些城市的商业银行根据《商业银行服务价格管理暂行办法》的规定，开始征收专门针对硬币储蓄的“硬币清点费”，如农行规定存入200枚硬币收5元手续费，每增加100个，加收1元；工行则为100枚收取5元；等等。商业银行的做法（   ）