欢乐谷Don’t stop when you’re tired. Stop when you’re done.

看第We sing patriotic songs during the national holiday celebration.​欢乐谷A baby babbles cute sounds before learning to speak.​

看第He drives across the country to visit all the national parks.​欢乐谷She paints murals on the walls of public buildings.​看第The snowstorm causes schools and businesses to close for the day.​

欢乐谷You study physics to understand how the universe works.​看第They travel by airplane to attend an international conference.​

欢乐谷I listen to the radio while driving to work each day.​

看第The fire provides light for us to see during the power outage.​欢乐谷The key to success is to focus on goals, not obstacles.

看第The harder you work for something, the greater you’ll feel when you achieve it.欢乐谷The only way to do great work is to love what you do.

看第Believe you can and you're halfway there.欢乐谷You don’t have to be great to start, but you have to start to be great.

(责任编辑：石小杰)