节省时间：save time/gain time/ less down time/salvage time
更严肃：more+serious/solemn/severe/sober/grave
以不同的方式：in different ways/in various ways
一个文静内向的孩子：a sedate and introverted(或endocentric/indrawn/introversive) child
例如：for instance/for example/such as
第一次做某事：the first time to do sth/the first time for sb to do.