题目内容：

With rising temperatures there’s concern for some freshwater fish. If the water gets too warm , then it can change their living activities .For some species in UK the river water needs to stay below 20℃. The problem is as the climate gets warmer so do the streams and rivers .The problem is particularly of concern for the smaller streams and rivers which respond to air temperature changes much more than the deeper and larger rivers .

The method to keep the temperatures of rivers down could be as simple as planting woodlands along the river course .Research has shown that trees cover lowland streams can keep water temperatures 5 ℃ lower than streams running through treeless environments .That 5 ℃  can make the difference between the water temperature being habitable for fish or being too warm for their living .

While it looks like a good method to a problem , there are things that need to be considered . We need to remember that trees are not the favorite habitat of all animals . Some of the habitats need open countryside . Trees can also bring their own problems .A nutrient  poor stream has its own life . Plant trees alongside it and leaves fall in the stream. Falling leaves can change the nutritional makeup of the stream , which will affect the stream and local species of the stream . You have to be careful with this type of management, but his method does offer a real chance to help freshwater living things against climate changes and increasing temperatures.

1.It can be inferred from the text that some freshwater fish ______.

A．have to live in the small streams and rivers

B．never need to change their living activities

C．are threatened by increasing temperature s

D．are becoming rare and expensive in the UK.

2.An easy method to protect freshwater fish is to ________ .

A．develop more different fish species

B．explore lots of fish protection areas

C．make streams run into the deeper rivers

D．plant trees around the streams and rivers

3.Which of the following statements is TRUE about the method ?

A．It brings problems if the water grows warmer

B．It needs little management .

C．It has its advantages and disadvantages

D．It is green but costs a great deal of money

4.What’s the main purpose of the text ?

A．To help people know more about freshwater fish

B．To introduce a method to protect freshwater fish

C．To explain why freshwater fish lost their habitat

D．To show how the weather affects freshwater fish .