乐观 (lè guān): 楽観的

Even though he didn't do well on the college entrance exam, he remained optimistic, believing that as long as he works hard, there will be many opportunities in the future.

When she was hospitalized, she was still so optimistic that she often told jokes to other patients and encouraged everyone to overcome the illness together.

Faced with sudden layoffs at the company, Xiao Li didn't despair; he optimistically thought it was a good opportunity to replan his career.

The weather forecast said it might rain on the weekend, but my younger brother was optimistic; he said it would be a good chance to watch movies at home and would be just as happy.

Although he failed twice in starting his own business, he always maintained an optimistic attitude, believing that the third attempt would definitely succeed.