题目

完形填空     Someone says, “Time is money.” But I think time is    1    important than money. Why? Because when money is spent, we can get back. However（然而）, when time is    2    , it’ll never    3   . That is    4    we mustn’t waste（浪费）time.     So we say that     5     is usually short. Even a second（秒）is very important. We should make full use of our time to do something    6    .     But it is a pity that there are a lot of people who do not know the importance of time. They spend their time smoking, dr如图是人体生殖发育过程示意图与子宫内胎儿、脐带和胎盘关系示意图，请根据图和所学知识，回答下列问题．（1）母亲的卵细胞是由[    ]    产生的，它和父亲的精子在[    ]    内相遇，形成    ，然后进入子宫，植入母体的[    ]    上．（2）人类胚胎初始发育的营养由    提供．[    ]    可以使胎儿在母体内的环境保持恒温，胚胎发育的过程中，通过[    ]    和[    ]    从母体获得所需的氧和养料．（3）胚胎在母体子宫里发育的时间一般为    天．