1-C. (4) Chinese would be most useful because China is a fast-growing economy.(4) Chinese would be most useful because China is a fast-growing economy.
(4)中国語は、最も有用であろう、というのも、中国は急成長している経済であるため。
2-C. China is a fast-growing economy and in the future it will become the world's biggest.China is a fast-growing economy and in the future it will become the world's biggest.
中国は急成長している経済です、さらに、将来的には、それは世界最大となります。
3-C. Mr. Uno, a businessman, wants to travel from Tokyo to Chicago by economy class at the end of September.Mr. Uno, a businessman, wants to travel from Tokyo to Chicago by economy class at the end of September.
4-C. City, Date, Time, Business Class, Economy ClassCity, Date, Time, Business Class, Economy Class
都市、日付、時刻、ビジネスクラス、エコノミークラス
5. However, with the Great Depression setting in and the Western countries launching economic blocs by involving colonial economies, Japan's economy suffered a major blow.However, with the Great Depression setting in and the Western countries launching economic blocs by involving colonial economies, Japan's economy suffered a major blow.
6. The question is whether our economy is governed by any kind of rule of law.The question is whether our economy is governed by any kind of rule of law.