题目

下列关于胎儿从母体获得营养物质的途径中，正确的是 A．母体 → 脐带 → 胎盘 → 胎儿 B．母体 → 胎盘 → 脐带 → 胎儿 C．胎盘 → 母体 → 脐带 → 胎儿 D．脐带 → 母体 → 胎盘 → 胎儿 答案：B【分析】 胎儿生活在子宫内半透明的羊水中，胎儿通过脐带、胎盘从母体获得所需要的营养物质和氧气，同时胎儿产生的二氧化碳等废物，也是通过脐带、胎盘经母体排出体外。因此，胎儿从母体获得营养物质的途径是母体 →胎盘 → 脐带 → 胎儿。故选 B 。 【考点定位】胚胎的发育和营养。 【名师根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。 Sometimes all a child needs is a little creative involvement from mom and dad. Here are some very simple easy-to-use ideas that might help. School is Important!    71    Consciously learn something new every day and make a game of it with your family. Make homework a family activity and participate by checking in and helping out. Set Realistic Goals. Be reasonable. Don’t expect miracles to happen overnight.    72    . Help your child understand what they’re trying to accomplish and that there are no short cuts. Improving their grades is a goal worth reaching, not a punishment.    73    . This will give them a say in their educational future. Be a Mentor(导师). Be available for your child. If you’re willing to sit down and help them get through a tough assignment, they’ll be more willing, too. Remember that learning is about encountering what you don’t know. That can be scary!    74    . Your child will learn more quickly if they can depend on you to help no matter what the problem is. Know When to Ask for Help. Know when to turn to a tutor, or any of the numerous programs connected with local schools and libraries,    75   . Consider seeking professional help. A counselor(顾问)should be able to identify problems and give suggestions on how to help a child learn to their full potential. A. Many children suffer from learning disabilities. B. Academic progress is a slow but steady process. C. Allow your child to suggest solutions to the problem. D. When your child succeeds make sure they are congratulated. E. Be patient when helping your child master new skills. F. Talk about how valuable education is and how it can benefit your child’s future. G. Establishing an environment where learning is fun and important is a great thing to do.