长白山，中华名山，是中国满族的发祥地和圣山．白云峰是长白山的主峰，耸立于天池西侧，海拔2691米，白云峰底生长着温带阔叶林，而峰顶却生长着针叶林，请问影响其植物分布的生态因素是（  ）

根据句意，用所给动词的适当形式填空。
（1）To keep safe, everyone____  (tell) to wear a seat belt in the car now.
（2）If we cut down the trees, floods____ (wash) our village away.
（3）The microphone is used to____  (make) your voice sound louder.
（4）All the team members were seen____  (train) hard when I passed the room.
（5）Mr. Dong ____  (live) here since he was born.

Nobody can imagine what difficulty we had ________ home in the snowstorm.