WATER SPORTS Recreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and equipment. Recreational scuba diving grew out of related activities such as snorkeling and underwater hunting. For a long time, recreational underwater...
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WATER SPORTS
Recreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and equipment.
Recreational scuba diving grew out of related activities such as snorkeling and underwater hunting. For a long time, recreational underwater excursions were limited by the amount of breath that could be held. However, the invention of the aqualung in 1943 by Jacques-Yves Cousteau and its development over subsequent years led to a revolution in recreational diving. However, for much of the 1950s and early1960s, recreational scuba diving was a sport limited to those who were able to afford or make their own kit, and prepared to undergo intensive training to use it. As the sport became more popular, manufacturers became aware of the potential market, and equipment began to appear that was easy to use, affordable and reliable. Continued advances in' SCUBA technology, such as buoyancy compensators, modern diving regulators, wet or dry suits, and dive computers, increased the safety, comfort and convenience of the gear encouraging more people to train and use it.
Until the early 1950s, navies and other organizations performing professional diving were the only providers of diver training, but only for their own personnel and only using their own types of equipment. There were no training courses available to civilians who bought the first scuba equipment. Professional instruction started in 1959 when the non-profit National Association of Underwater Instructors was formed.
Further developments in technology have reduced the cost of training and diving. Scuba-diving has become a popular leisure activity, and many diving locations have some form of dive shop presence that can offer air fills, equipment and training. In tropical and sub-tropical parts of the world, there is a large market in holiday divers, who train and dive while on holiday, but rarely dive close to home. Generally, recreational diving depths are limited to a maximum of between 30 and 40 meters (100 and 130 feet), beyond which a variety of safety issues make it unsafe to dive using recreation diving equipment and practices, and specialized training and equipment for technical diving are needed.
According to the second paragraph, in the 1950s and early 1960s, recreational scuba diving was a sport limited because _______.
A. divers did not like to take part in any intensive training courses
B. there were not any intensive training courses for divers
C. there were not enough kit for many divers
D. kit and intensive training were too expensive for many people to afford
Đáp án C
Mũ bảo hiểm mà các thợ lặn cung cấp bề mặt sử dụng ngày nay được sản xuất là gì, theo đoạn văn?
Một ly
B. đồng
C. nhựa
D. canvas