The moment ______Leo will never forget is______he joined the Air Force

Clean water and fresh air are essential for our daily life, _______ we can’t live.

Many died or returned home, but most remained in California to________a life for themselves in the new towns or on farms.[ ]

To be honest, every season of the year I do ___________watching tulips in Ma’an chi park.

6The album (相册) is__________to me as it keeps a record of my childhood life