The secret world of ANIMALS: modal verbs

Meet the Giant Rats That Are Sniffing out Landmines African giant pouched rats – huge, cat-size rodents native to central Africa – have bad vision, but an extraordinary sense of smell. This makes them perfect candidates for discovering hidden landmines by sniffing out the explosive TNT.Even decades after conflict, explosives remain buried in the earth, maiming and killing thousands of people who stumble across them each year. In 2013, mines and other buried explosives caused 3,308 casualties worldwide.Finding these hidden explosives is challenging and dangerous. People with metal detectors not only risk their lives, they work slowly, stopping to investigate every suspicious ping. Trained dogs, while commonly used, are expensive and tough to transport.APOPO, a Belgian non-profit, has created an army of TNT-sniffing African giant pouched rats. They are light enough to walk over the mines without setting them off, and they use their noses to find the explosives quickly.Since APOPO was founded in 1997, these furry super-sniffers have helped clear 13,200 mines from minefields in Tanzania, Mozambique, Angola, and, most recently, in Cambodia.Training the rats to sniff out landmines isn’t easy, though. For one thing, the rats need to learn how to be around humans, starting at infancy. For another, they don’t respond to verbal commands, so the trainers have to teach them that hearing a click means they get a food reward. The last step is hooking the rats up to harnesses and teaching them how to walk on a rope grid in the field.When the trained rats find a landmine, they stop and scratch at the TNT-scented spot, which the human de-miners mark and come back later to excavate. If they find a mine, they detonate it on site.This whole training process takes about nine months for every rat. And there's a downside—the animals only live about eight years, which means a lot of training for an animal with a relatively short time span. Sort the statements based on whether they are TRUE or FALSE. TRUE African rats can't see very well. Trained dogs are not so easily transported to various places. The rats don't respond well to words. The rats don't weigh much, so they don't activate the explosives when they walk over them. FALSE African rats are only used to find landmines in Africa. There isn't much training necessary for the rats to be able to find a landmine. The rats can walk freely in the minefield. The rats use their sight to detect landmines quickly. When they find a mine, the rats stop and dig it out. Human de-miners can find mines more quickly than the rats. The Secret World of Animals Now take a look at the text from your books (pg. 50). Read it and find out more about how people used other types of animals to help them. Match the animals and the things they can do. dogs can act as guides for the blind pigeons can carry messages rats can find landmines MODAL VERBS Watch the video to learn about modal verbs. Modal and related verbs Modal auxiliary verbs are used to expess (un)certainty in a situation.There are a number of rules for modal verbs:They are unchanging (i.e. there is only one form) so they don’t take 3rd person -sand can’t have an -ed past form. Sometimes, couldis referred to as the past form of canbut it is, in fact, a separate verb which sometimes has this function.They cannot be preceded or followed by to.You cannot use two modals together.To talk about a present or future situation, they are always followed by a verb in the infinitive withoutto.To make questions with modals, we invert the subject and the modal verb. (I can -> Can I?)To make negatives with modals, we add notto the modal. ( I can -> I cannot more on modal and related verbs, check your books (pg. 132). Rewrite the sentences so that they mean the same, using the words in capital letters.Make sure that you use the same verb tense as in the given sentence. Example:I have to wear a uniform at school. (REQUIRE)I am required to wear a uniform in school.1. We have to be home by ten o'clock. (REQUIRE)We are required to be home by ten o'clock.2. I could wear what I wanted. (ALLOW)I was allowed to wear what I wanted.3. I had to put on a Harry Potter costume. (OBLIGE)I was obliged to put on a Harry Potter costume.4. I should read about the history of fashion. (OUGHT)I ought to read about the history of fashion.5. I wasn't required to cut my hair short. (HAVE)I didn't have to cut my hair short. Choose the phrases which could replace the underlined words.1. He's amazing. When he was only 8 years old, he could speak three languages. had the ability was allowed to 2. Can you come out with us tonight? Have you got the ability to Have you got the permission to 3. Hemust be out. There are no lights on. He is obliged to be I'm sure he is 4. You should do some shopping for your mum. I advise you to It is your duty to 5. They could be at the cinema. I remember Mark talking about it earlier. It is possible that they are They have the ability to be Choose the correct answers.1. You _ tell anyone. It's a secret. mustn't don't have to 2. Don't worry. You're _ to pass your driving test one day. Keep trying. bound supposed 3. Don't touch anything. There _ be a trap. might can 4. You are _ to leave the country so, please, hand over your passport. obliged forbidden 5. Next year, I'll _ join the club. can be able to 6. They _ have gone home. I don't see them anywhere. might can't 7. Many accidents _ be prevented with a little care. could must 8. Mr Morris _ be nearly ninety years old but he doesn't look like it. can't must 9. The $55 passport fee _ accompany your application. must need 10. When we were children, we didn't have e-mail so we _ write letters. must had to 11. We _ meet again tomorrow - I can finish the job on my own. mustn't won't have to 12. You _ stay in a hostel. You can stay with us. mustn't don't have to 13. He _ run to the station because he was late. must had to 14. Attention, please! All accidents _ be reported to the safety officer. must have to 15. The children will be safe with me so you _ worry. don't need needn't