Bài tập tiếng Anh lớp 12 Unit 12, 13, 14 có đáp án

The primary attraction of snorkeling is the opportunity to observe underwater life in a natural setting, such as coral reefs, fish, starfish, and mollusks. Other organisms that can be seen while snorkeling include various forms of seaweed, jellyfish, shrimp and $ea turtles. Snorkeling requires no special training, only the ability to swim and to breathe through the snorkel. However, it is considered advisable that one get some instruction from a tour guide, dive shop, or equipment rental shop, any of which often can be found around popular snorkeling locations. Instruction generally covers equipment usage, basic safety, what to look for, and what to look out for, including how not to damage fragile organisms such as coral. As with scuba diving, it is always recommended that one, should not snorkel alone, but rather with a friend, a guide, or a tour group. Swim fins used in snorkeling are usually longer than those used in diving. Snorkel is a tube about thirty centimeters (twelve inches) long, usually J-shaped, fitted with a mouthpiece, and constructed of rubber or plastic. It is used for breathing air from above the water surface when the mouth and nose are submerged, either when snorkeling or during a surface swim before or after scuba diving. The snorkel usually has a piece of rubber that attaches the snorkel to the outside of the strap of the diving mask, as sticking the snorkel in between the strap and the mask could cause the mask to leak, or risk losing the snorkel should the diver choose to switch to scuba. Typically, the diving mask also serves to prevent breathing through the nose, so that one is forced to breathe through the snorkel. This also provides some negative pressure which helps keep the .mask sealed against the face, though attempting to breathe out through the nose can break this seal and fog the mask

Scuba diving is a beautiful (16) _____, which allows people to view a whole different world. We enter (17) _____ unknown world in which the danger of scuba diving has been taken into account. The dangers all into two groups: those in the ocean itself and that of the individual. There are (18) _____ many things that the beginner diver needs to remember and understand. A comprehensive scuba diving course is (19) ___ because there are lessons which you need to know and understand before even going near the ocean. In all the parts of the training, always diving with a partner is (20) _____ to be very important to reduce danger and the diver and hid friend can observe each other at all times during any dive. It is advisable to have a partner who is a more experienced diver with a new diver, or someone who .is not confident (21) _____. The reason for learning skills which is prior to getting into the ocean has two effects. The first one is the (22) _____ to know what to do in a situation. The second one is to have the confidence to carry out the actions without panic. Panic is a danger that will take away the taught skills as it is an emotional response. The other dangers of scuba diving are in the (23) ___ life. Having some knowledge of the underwater life of the area you are diving in, can make you (24) _____ of the risks. This means you can avoid animals which may become aggressive when approached. Also you need to know the poisons or sharp teeth that could be a problem in this world, which is new to you. The many dangers of scuba diving are real and knowing what to expect and. How to deal with it can (25) _____ you safe.