Definition: Tough people are mentally strong and not afraid of difficult situations. Level: B2
要在竞争激烈的商业世界中生存，你需要意志坚强。
You need to be ___tough to survive in the competitive world of business.
这本书讲述了一个永不放弃的、意志坚强的渔民的故事。
The book tells the story of a ___tough fisherman who never gives up.
