下列各句中，划线的成语使用正确的一项是（  ）

在下面一段文字的横线处补写恰当的语句，使整段文字语意完整连贯，内容贴切，逻辑严密。每处不超过15个字。

    光，是人类的好朋友，①____。然而，光一旦变成污染，②____：比如过强过滥的光、变化过于迅速的光会破坏植物的生长规律，会影响影人的生理与心理正常。现在，国内不少城市还在不惜重金打造一座座“不夜城”，而这些所谓的“不夜城”恰恰是光污染的重灾区。看美国大片，总以为纽约是一座不眠的美丽城市。其实纽约对夜间强光和霓虹灯的照明时段和适用地段都是有严格规定的。由此可知，③____，光是可以起到美化环境的作用而不是制造光污染的。

形成西北干旱、半干旱地区以干旱为主的自然特征的原因是（ ）
①距海洋远
②终年受副热带高气压带控制
③高大山地尤其是青藏高原隆起对水汽的阻隔作用
④纬度位置高

    Today is Saturday. In the morning, Xiaoyong is sleeping, but the phone rings. He wakes up from his dream. He gets up and goes to the park near his home. He is doing exercise, but it starts to rain. He has to go home. He is doing his homework at home, but the bell rings.

    In the afternoon, Xiaoyong is riding his bike, but suddenly(突然)a little dog runs to him. He falls off his bike. He is so sad.