Sharks are (18) Sharks of the most frightening creatures in our oceans. They are well prepared for feeding under water because they can (19) very well, and they can also feel movement through special lines on the sides of their bodies. These make sharks very dangerous for (20) creatures that become their food. Although sharks are similar (21) ways, their bodies are different. For example, unlike other fish, most sharks (22) time in order to breathe and stay alive, (23) sea other fish in a number of to swim all the they hardly sleep at all. Also, if sharks are turned over on their backs, they can stop moving completely. This is a very useful technique for researchers are often required to handle sharks. It allows them to (25) (24) fascinating creatures. out more about these 18. A one B some 19. A seeing B sees C any C saw D many D see 20. A smaller B most small C smallest D more small 21. A with B from C to D of 22. A can B need C must D should 23. A so B as C but D or 24. A which B who 25. A found B finding C what C find D whose D finds​