Unit 13 We're trying to save the earth 第2课时 Section A(3a－3b)(word)-【全效学习】2023-2024学年九年级全册英语同步课件及教参（人教版）

第2课时　Section A(3a－3b) Ⅰ.用括号中所给单词的适当形式填空 1．There are many old books on __sale__(sell)in the bookstore. 2．We should protect pandas because they are __endangered__(danger)animals. 3．WildAid and the WWF are both __environmental__(environment)protection groups. 4．Smoking is __harmful__(harm)to your health.You must give it up. 5．Tom is one of the __strongest__(strong)boys in our class and he likes doing sports very much. Ⅱ.用方框中所给短语的适当形式填空 cut off；at the top of；each time；be good for；no longer 1．The class had a picnic at the top of the hill. 2．Eating less junk food is good for our health. 3．It's said that Helen no longer practices the piano. 4． Each time you make a decision，you should think carefully. 5．Mike's middle finger was accidentally cut off by the machine while he was working. Ⅲ.阅读理解 Many people are afraid of sharks，but they usually do not know much about them.For example，there are at least 350 kinds of sharks，and all of them eat meat.Some sharks are very big.The whale sharks are 9 to 14 meters long.But some sharks are very small.The spined pygmy sharks are only 18 to 28 centimeters long.Sharks have a very long history.In fact，the earliest known sharks date back to more than 420 million years ago.Today，sharks live in every ocean in the world，but most sharks live in warm water.They keep the oceans clean because they eat sick fish and animals. Most sharks have four to six rows of teeth.When a shark's tooth falls out，another tooth moves in from behind.“__▲__” However，they'll “hear” sounds and movements in the water.When any sound of movement makes the water vibrate(振动)，sharks can feel these vibrations，and these vibrations can help sharks find food.Sharks use their large eyes to find food，too.Most sharks can see clearly in little light.They often look for food in the dark，in the evening，or in the middle of the night. Scientists want to learn more about sharks for several reasons.For example，cancer(癌症)is common among many animals and people.However，few sharks have it.S