进入青春期,我们生理上都发生着显著变化,下面对此说法正确的是( )①这意味着我们已经长大成人了②这些变化都是正常的③这是我们从童年向成年过渡的必然变化④主要体现在身体外形、内部器官与性机能的变化
--- Red-crowned cranes need more people’s help. ---Yes. People working in the reserves are doing everything they can ____these birds.
---I often hear a new-born baby next door __________ a lot at night. ---Maybe the baby is hungry then.
About seventy percent of our earth _______ by water.
Today the forests are getting fewer and fewer. We must______ down too many trees.
What’s the sentence structure of “ Spring is warm and sunny.”?