My new Chinese teacher is Miss White. She is funny and kind. Her favourite food is salad because it is fresh and healthy. She can sing English songs and play the guitar. There is a lake in front of her house. Behind the house, there is a mountain. So she often climbs the mountain and plays some sports on the weekend. I like my Chinese teacher.

填空完成人的生殖与发育过程（写出数字所代表的结构名称）：

①____②____③____④____．

某实验小组的同学在实验室中，用天平和量筒测量一块体积不规则的金属块的密度，进行了如下的实验操作：

a．将金属块浸没在量筒内的水中，测出金属块和水的总体积

b．用天平称出金属块的质量

c．将适量的水倒入量筒中，测出水的体积

d．计算出金属块的密度

正确的实验操作顺序是（　　）

已知一个不等式组的解集如图所示，则以下各数是该不等式组的解的是（   ）