1 . Handshaking ________ have started as an ancient custom to demonstrate to a stranger that you had no weapon in your hand. (用适当的词填空)

2 . At the same time, live, detailed maps of Earth’s surface ________ aid humanity in amazing ways. (用适当的词填空)

3 . If you don’t know the names of certain people, you ________ be able to ask older relatives, thereby involving them in your research. (用适当的词填空)

4 . A teacher ________ read 10,000 essays over a 40-year career. A machine can read millions of essays within minutes. We have no chance of competing against machines on frequent, high-volume tasks. (用适当的词填空)

5 . The giant “snowflake” was made from 91 smaller ________, each with the name of a participating country or region. According to Zhang, to combine the smaller snowflakes symbolizes people’s joint efforts to build a community with a shared future for humanity and only through such efforts ________ man overcome the pandemic (流行病). (用适当的词填空)

6 . The slow growing lichen (地衣) and mushrooms upon which the reindeer depend for survival are not found in plantations. So, the death of one __________ mean the death of the other, and an uncertain future for an entire people. (用适当的词填空)

8 . This _____ sound crazy but I was on my way to drop some of my mother’s things off at the charity bins. (用适当的词填空)