下面的短文后列出了7个句子，请根据短文的内容对每个句子做出判断;如果该句提供的是正确信息，请选择A;如果该句提供的是错误信息，请选择B;如果该句的信息文中没有提及，请选择C。
Mau Piailug , Ocean Navigator (文章整理中……)
16. At the time of his voyage, Mau had unique navigational skills.
A. Right B. Wrong C. Not mentioned
17. Mau was familiar with the sea around Tahiti.
A. Right B. Wrong C. Not mentioned
18. Mau could not afford a compass or charts.
A. Right B. Wrong C. Not mentioned
19. Mau learnt navigation skills from his grandfather.
A. Right B. Wrong C. Not mentioned
20. Mau used stones to memories where the stars were situated in the sky.
A. Right B. Wrong C. Not mentioned
21. The first inhabitants of Hawaii could read and write.
A. Right B. Wrong C. Not mentioned
22. Mau expected his students to remember the positions of the stars immediately.
A. Right B. Wrong C. Not mentioned
参考答案：A、B、C、A、A、C、B