题目内容：

    Feeding birds is a popular way to watch wildlife.But experts say it might put wild birds at risk.

Feeding birds is not necessary for their survival except in extreme weather conditions.Feeders(喂食器)can definitely help birds get through that kind of weather.But most birds eat insects and show little interest in bird feeders.For those birds，we can grow native plants in a natural environment.Birds which are fond of eating seeds will be more likely to come to feeders if there is some cover nearby.This lets them feed and then fly to protective areas，such as in trees.

The most common mistake people make with their bird feeders is that they put feeders in places where birds are easily frightened by passers-by，risk being hurt by cats，or risk flying into windows.

So set up a bird feeder at least one meter away from a window.That way，if a bird gets frightened，it won’t get killed when it hits the glass.Owners of cats should keep them inside home so they can’t hurt the birds.

Some birds are more aggressive at feeders.They eat a lot and do not leave much food for other birds.A solution is to put the food in more than one place by using different kinds of seeds or fruits.This can also increase the number and diversity of birds in your neighborhood.But don’t feed wild birds anything salty，like potato chips，or food that could choke them，like bread.

Pay attention to food quality and freshness.Unprotected food left too long in feeders will turn moldy(发霉)，which can kill wildlife.

Another word of advice:Always provide a supply of clean water for birds，but use care when looking for the right birdbath.If the birdbaths are too deep for birds，putting a few large stones in the water can give the birds a place to sit.

1.What’s the most common mistake about feeding birds?

A. Putting feeders in improper places. B. Providing food in inappropriate time.

C. Leaving feeders unprotected. D. Supplying dirty and deep water.

2.Which of the following may not be suitable for feeding birds?

A. Seeds. B. Bread. C. Fruit. D. Insects.

3.The author advises helping more birds by_________.

A. increasing the number of feeders

B. cleaning the birds with clean water

C. putting more large stones in the feeders

D. keeping aggressive birds away from the feeders

4.What is the text mainly about?

A. Problems with bird feeding.

B. Where to place bird feeders.

C. Popular ways of protecting wild birds.

D. How to feed wild birds safely and healthily.