下列诗句中描述生物影响环境的是

空降兵某部官兵使用新装备进行超低空跳伞，若跳伞空降兵在离地面224m高处，由静止开始在竖直方向做自由落体运动．一段时间后立即打开降落伞，以12.5m/s²的加速度匀减速下降．为了空降兵的安全，要求空降兵落地速度最大不得超过5m/s．则空降兵打开降落伞时离地的高度至少为多少米？（g取10m/s²，不计空气阻力）

用所给动词的适当形式填空，完成短文

 Children’s Safety

I ____(talk) to some students. I ____(ask) about safety rules when they ____(be) younger. Their rules were very good.

John ____(say), “I couldn’t play in the kitchen.” His mum and dad didn’t ____(like) that.

Jennifer ____(can) play the piano and she could also ____(play) games in the living room. When her mum and dad ____(not, be) home, she couldn’t cook.

Tom could play in the bedroom or the living room. He couldn’t ____(play) in the bathroom or the kitchen.

What ____(be) your safety rules when you were young? ____(talk) to younger students about these and ____(help) them.