在中国近现代史上，国共关系的发展演变，影响着中国历史发展的进程。阅读材料，回答问题。

材料一  ……军校的创办，是国共合作的产物，它为国共两党培养了许多军事将领和军事骨干，为东征、北伐战争和抗日战争的胜利做出重要贡献……

——姜廷玉（军事博物馆研究员） 

材料二  1927～1937年间，国民党各派军事集团的混战，特别是蒋介石发动的对红军的几次“围剿”，既给中国人民带来无穷灾难，又给日本帝国主义发动大规模侵华战争以可乘之机。

——摘编自《内战百科》

九一八事变纪念碑

材料三  四万万同胞，同仇敌忾，用自己的血肉筑起了坚不可摧的长城，使日本侵略者陷入人民战争的汪洋大海之中。***领导的人民武装力量抗击大部分日军和几乎全部伪军。国民党爱国将士也在正面战场英勇抗击日军。

——人民日报社论《和平与正义是不可战胜的》

宋代是我国历史上繁荣时代。结合所学回答问题。

阅读理解

A report by UNEP联合国环境规划署（United Nations Environment Programme） says that by 2050, the world's population is expected to reach 9.6 billion and feeding us all will require at least 60% more food than we have ever produced before. What's more, if we can't find out a way to do with it, food shortages (短缺) could be a big problem.

A main purpose of the report is to make people be aware of the importance of this challenge. In the past, food production increase relied on the practices like cutting down trees, using chemicals and wasting water. Today we understand the environmental price of those techniques.

“The question now is how to produce much more food and at the same time avoid all the environmental problems that we had in the past,” Searchinger, a famous scientist said.

We need to develop new ways to produce food. We can no longer cut down trees. Instead, we'll have to protect water and land, and reduce air pollution.

The report also mentions the importance of reducing food loss and wasteAccording to the United Nations, the waste adds up to one-third of all the food we produce —an amount that could feed an additional 2 billion people.

The report also suggests that we make changes in our diet. “You have to eat more efficiently (有 效地),” said Searchinger, “and above all that means eating less meat, and especially reducing the growth of beef.”That's because raising cows is an inefficient way of producing food. Of all the energy that goes onto feeding cows, only about 1% is converted (转换) into food for people.

根据短文内容填空。

    In the coming summer holidays, you will probably visit the Shanghai Expo. Before you head off the Expro, please read the following tips so that you behave properly and show off China's best face to visitors from other countries.

When waiting in a line

    Wait patiently instead of cutting to the front of the line. If you have to leave your spot in line and want to come back, tell the people standing in front of and behind you. Ask them to kindly hold you spot, and thank them when you return.

When touring the Expro

    Don't touch or climb on exhibits. Visitors are allowed to take pictures and videos around the Expro, but when cameras are not welcome, don't turn yours on. If souvenirs are handed out, don't push and scream. Be polite and wait your turn.

When attending shows

    If you are late, wait until the break to enter. It will disturb other audience if you walk in late.

    It's very important to leave in the middle of a musical or stage play. If an early exit is necessary, you can leave after a scene is over.

Keep quiet during a performance. Before the performance starts, either turn off your mobile phone or set it silent mode. Never answer your phone while a performance is going on.

    After an excellent performance, clap your hands warmly. Don't laugh at the performers when they make mistakes.

When having meals

    Don't talk loudly at meals. With many hungry visitors waiting, don't stay too long at your table after you have finished. Politely move on to another place.