London is such a wonderful city. It is very large. The Thames River runs 1 the city from west to east. So the city has 2 parts:    the South and the North. In the North, there are important buildings, shops, big parks and interesting places.
The weather in London is good. In winter it is not very cold and in summer it is not very hot 3 the city is near the sea. People say 4 London is a foggy city and it often rains. It is true.
   Last year, when I 5 in London I met one of the 6 fogs in years. You could hardly see your hand in front of your face. Cars and buses moved along with their lights on. When evening fell, the weather 7 even worse. The fog was as thick as milk.8 the buses and cars stopped. I happened 9 an important meeting on the other side of the town, but it was impossible to find a car. I had to get there 10.

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按时间按先后顺序排列下列史实，正确的是（    ）

①中共提出建立全国抗日民族统一战线的主张  ②西安事变  ③抗日民族统一战线初步形成  ④九一八事变后，民族矛盾上升