The first question. Exchange rate is the ratio of RMB to foreign currency. For example, 100 RMB can be exchanged for 10 USD. The foreign exchange rate has gone up, so we have to change more than 10 into 10. It means that the RMB is not as valuable as it used to be, or it has depreciated.
The second question. The first half of the sentence is correct. The second half sentence is wrong. There should be a saying in the book that history always moves forward, although there will be twists and turns. Its development is also objective, but it will be influenced by human subjectivity. Not domination. For example, people can't stop the development of society. For example, the astronomical discoveries of Galileo, Copernicus and Bruno were strongly suppressed by the church. Although they had an impact at that time, a few years later, the world accepted scientific ideas.
The third question, at first glance, is correct. In fact, the second half sentence is wrong. You can understand it this way, which is right-the world is a universally connected whole, and nothing exists in isolation.
Do you understand?