20.A
2 1. Analog-digital conversion
24.D
Hemudu is located in the complex environment of lakes, swamps, plains, grasslands, hills and hills.
28.A
30.B
3 1.B
32.C
33.C
34. There are different opinions about the name of Yuyao. Said, "local customs", shun fief, shun surnamed Yao, hence the name Yuyao ("Shu fief, shun surnamed Yao, hence the name Yun Yuyao"). On the other hand, the Yue Jue Shu has been edited, and Xia Shaokang sealed it as nothing in the record, which is to serve, and Yao is its first city, so it is called Yuyao. "Shan Hai Jing" Guo Pu notes that Yushan is in the south of Yuyao County in Huiji and in the north of Zhang Ju County, so the two counties are named Yun, which is the third statement. There is also a saying called "Yushan in the city and Yaojiang in the south", hence the name. Furthermore, the Ming Dynasty's Interpretation of Counties and Counties said that county officials would meet records, and there was a Yao surname in Yuyao, Shanxi and Hedong, so it was called Yuyao. Recently, someone claimed that Yuyao was a Vietnamese place name, and the meaning was clear.
35.B
36.D
37.A
39.B
4 1.B
42.A
43.B
44.C
45.B