1. To motivate yourself for any achievement requires clear goals and an optimistic, can-do attitude.
    要激励自己获得成就需要有明确的目标，以及一种乐观的、"我能行"的态度。

2. He is optimistic that once parents make a commitment to the program, they will be daily role models for their children, unlike parents whose children are in boarding schools.
    他很乐观地相信，一旦家长们投入到计划当中，他们就会成为孩子们日常行为的榜样，这一点与寄宿学校的学生家长完全不同。

3. As I get older I get more optimistic.
    我越活越乐观。

4. Although negotiators are optimistic, the details are complex enough that they may be hard-pressed to get a deal at all.
    然谈判代表持乐观态度，但协议细节如此复杂，他们所面临的困难很可能使他们无法取得一致。