B3 Rewrite the sentences below without it.
1 It is about 300 kilometres from Nanjing to Shanghai.

2 In winter, it is very cold in Shenyang.

3 It is 6 p.m. when I have dinner.

4 It is 26 June today.

5 It will be a fine day tomorrow.

6 It is on Sunday afternoon when he often goes to Sunshine Library.

7 It is not far from the park to the post office.

8 Is it 31 December the day after tomorrow?

9 It is $39° C$ today. I feel very hot.

10 It was 7:30 a.m. when she got to the airport.

1. The distance from Nanjing to Shanghai is about 300 kilometres.
2. In winter, Shenyang is very cold.
3. I have dinner at 6 p.m.
4. Today is 26 June.
5. Tomorrow will be a fine day.
6. He often goes to Sunshine Library on Sunday afternoon.
7. The park is not far from the post office.
8. Is the day after tomorrow 31 December?
9. The temperature is 39°C today. I feel very hot.
10. She got to the airport at 7:30 a.m.

这些句子中的it均为形式主语，分别指代距离、天气、时间、日期等。改写时需将真正的描述对象（如距离、地点、时间、日期等）提前，还原句子的真实主语结构，去掉形式主语it，使句子语义清晰且符合语法规范。