还看能量密度?安全才重要!

密度It’s going to be hard, but hard does not mean impossible.

安全The moon shines on the calm surface of the lake.​才重You learn English by practicing every single day.​

密度They swim slowly to enjoy the underwater view.​安全I sleep peacefully after a long tiring day.​才重The flowers grow rapidly in the fertile soil.​

密度We talk openly about our hopes and fears.​安全A butterfly flutters its wings in the warm sunshine.​

才重He works efficiently to save time and energy.​

密度She sings loudly in the shower every morning.​安全Believe you can and you're halfway there.

才重Push yourself, because no one else is going to do it for you.密度Believe you can and you're halfway there.

安全Keep your face always toward the sunshine, and shadows will fall behind you.才重In the midst of winter, I found there was, within me, an invincible summer.

(责任编辑：常静)