题目内容：

A long time ago, before human beings lived on the earth, little coral polyps（水螅）settled around tropical （热带的）coastlines and constructed corals. Over a long period they created lots of reefs. Yet, pollution, climate change and commercial fisheries are limiting the chance of future generations knowing or seeing many of the reefs and sea creatures that exist. Hence, take action to dive now and you can explore the underwater world.

Commercial underwater diving began in ancient Greece. Diving in general means that the whole body is completely in water. On that account there are lots of exciting and quite adventurous ways to dive, like shark cage diving, scuba diving（戴水肺潜水）and reef diving.

There are great coral reefs all over the world, but usually they are situated in warm, clear water such as the Pacific and the Indian Ocean, where they grow best. This is why there are no coral reefs on the west coast of South Africa. However, South Africa’s east coast offers much brightly coloured sea life.

In South Africa more than 100,000 dives a year are made just in coral reefs, which are one of the natural wonders of the world. To see the whole beauty of the reef the right diving gear（设备） is an essential requirement. This means a perfect fitting diving mask and fins, as well as a snorkel（呼吸管）and a friend. Diving alone is dangerous because there may be strong currents you are not aware of, and it’s a lot more fun to share the experience with someone. However, before you can explore the deeper sea, a certificated and checked scuba, a wetsuit and of course a license will be needed. Whether you choose the snorkel or the scuba to spot the colourful underwater world, try to touch as little as possible, be careful with the corals and don’t strike the fishes, because the complex ecosystem is very sensitive.

1.The following factors probably affect coral reefs EXCEPT ________.

A．sea creatures      B．pollution          C．fishing            D．climate change

2.Which of the following is true according to the passage?

A．Human beings appeared before corals were created.

B．One needs a license to dive into the deeper sea.

C．Diving alone has many advantages.

D．The origin of diving is in modern Greece.

3.There are no coral reefs on the west coast of South Africa probably because of a lack of ________.

A．large waters and soft sand

B．warm currents and delicious food

C．friendly creatures and flat seabed

D．clear water and suitable temperature

4.The last paragraph mainly tells us ________.

A．diving alone under the sea is rather dangerous

B．some matters we need pay attention to when diving

C．South Africa is a popular place for diving

D．what we should wear when diving