题目内容：

    Today，we are constantly bombarded with media reports about research on the right diet to follow to help us maintain a healthy lifestyle or lose weight—but it’s hard to know which one to pick and，once chosen，it's harder still to stick to it.And now there’s another choice to get our teeth into.

A flexitarian(弹性素食者)diet involves eating plant—based foods and only occasionally eating meat and fish.This eating style allows you to supplement some ingredients that you wouldn’t get in a stricter vegan(素食主义者)diet—another trend growing in popularity.And like veganism，flexitarianism isn’t about eating carefully to help you lose a few pounds—it’s something people choose for ethical reasons，to help the planet.And a study into the global food system and how it affects the climate，has found that eating mainly plant-based foods is one of three key steps towards a sustainable future for all by 2050.

This research found that food waste will need to be halved and farming practices will also have to improve to achieve this.But without a single solution，a combined approach is needed.Dr Marco Springmann from the University of Oxford was one of the lead authors of the report.He told the BBC“We really found that a combination of measures would be needed to stay within environmental limits and those include changes towards healthier more plant—based diets.”

But whereas vegans think it's wrong for animals to be killed for food，flexitarians believe eating meat once in a while is acceptable.And Dr Springmann agrees—as long as we“treat it as a luxury，it’s probably OK but you shouldn’t have more than one serving of red meat，which includes beef and pork，per week.”And here’s another fact to digest:If we moved to this type of diet，the study found that greenhouse gas emissions from agriculture would be cut by more than half.

1.What is the purpose of the first paragraph?

A. To lead to the topic. B. To entertain the readers.

C. To ask for information. D. To present an idea.

2.From the text，we can know that a flexitarian diet__________.

A. is the most popular eating style B. involves eating no meat

C. benefits the environment D. only balances the nutrition

3.What does Dr Marco Springmann agree with?

A. It’s wrong to kill animals for food.

B. Improving farming practices makes no sense.

C. A plant-based diet has nothing to do with climate change.

D. Combined measures are needed for environmental protection.

4.What can be the suitable title for the text?

A. Methods of keeping fit B. Choose a flexitarian diet

C. Measures to protect the environment D. Keep a strict vegan diet