4 . 根据语境，选择下框中的单词，必要时用其正确的形式替换句中划线部分的单词，使之意思一致。

embarrassed， convince， appetite， invaluable. pose， distinguish， occupy， characteristic， avallable， alternative

1. He is well known for his profound learning in mathematics.
2. The boy is engaged in planning his summer trip.
3. Mary was so awkward. She could only hide her face in shame.
4. I've been trying to persuade him to see a doctor
5. Parents transmit some of their features to their children
6. When he was a child, he had a strong desire for knowledge.
7. These data are not readily obtained if you haven't done some deep research.
8. Some of the measures put in place to deal with the crisis could cause a threat to British interests.
9. Finding himself under fire from all quarters, he had no choice but to abandon his scheme.
10. Experts say it's an precious social practice that results in big benefits.

5 . One of the________ of the National Games was the participation of Tokyo 2020 Olympians. （根据句意填空）

6 . 鼓浪屿是游客们必去的，有着狭窄的街道，漂亮的海滨和不同寻常的建筑。
________ Gulangyu Island, ________, ________, and________.

7 . The idea behind couch surfing is that travelers find free________ (住宿), from simple couches to spare bedrooms, in the homes of local people. （根据汉语提示单词拼写）