题目

一艘船，停在海面上利用声音的反射向海底垂直发射声音，经测量，从发射到接受到回声，所用时间为10秒，求海底的深度?(已知：声音在海水中的传播速度为1450米／秒) 答案：解、t=10s/2=5s   v=1450m/s S=vt=1450m/s×5s=7250m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。选项中有两项为多于选项。A strong vocabulary helps develop understanding, communication and reading ability. 【1】 Consider the following tips on helping your child develop an impressive vocabulary.Let Your Child Tell the StoryPerhaps you read nightly to your child or take turns doing so. Of course, this is an excellent way to expand reading and vocabulary skills. 【2】 Then, let your child charge the end of the rope of his imagination wherever his imagination leads.【3】 In short, you need to take an active role. If you want your children’s language skills to improve, take their vocabulary questions seriously. When they express curiosity about a word, be sure to teach the correct definition and pronunciation.Correct Mistakes with Care【4】 However, it’s essential not to scold them when they make such mistakes. Rather, point out what they got right, and then review the proper way to use and or speak the word. The more fun and positive an experience, the more interested and able your children will be in expanding their vocabulary.Do Be PatientYou may need to repeat words and meanings many times before your child fully grasps the concept. This is completely normal. 【5】 Children develop at their own paces. The most important thing is to honor and balance their needs so that learning doesn’t become struggle. While you want them to get ahead, you don’t want them to develop pressure with trying to do so.A. Try Your Best to Correct Them.B. Pay More Attention to Your Kid’s Vocabulary.C. It’s natural for children to mispronounce or misuse new words.D. It’s important for children to mispronounce new words while learning.E. That’s why parents should do what they can to help kids learn new words.F. Further, if your neighbor’s child has twice the vocabulary yours does, it’s not worth stressing over.G. However, on occasion, feel free to put the book down and ask your child to create a story to tell you.