下面是同学们身边的事例，其中描述正确的是（ ）
A：使用测电笔可以测出通电电灯的电流
B：安全带的作用是防止汽车紧急刹车时由于惯性而被撞伤
C：抱着竖直在地面上的钢管匀速下滑的消防队员与钢管间的摩擦是滚动摩擦
D：农村建房子时，用滑轮组提升材料，是因为滑轮组的效率比直接用手提升要高很多
①国家安全是国家生存与发展的重要保障
②国家安全是人民幸福安康的前提
③我国积累了巨大实力，不用担心国家安全
④维护国家安全的主要任务就是维护国土安全
(A)
I live in Shenzhen．Shenzhen is my hometown(家乡)．In spring，it's warm and wet．It always rains．But I don't like the rain．I can't go out to play．The summer in Shenzhen is very long．It is very hot and sunny．I can go to the beach．I can swim and play volleyball with my friends．The autumn in Shenzhen is very short．It's cool and windy．I can fly a kite on Lotus Hill(莲花山)．Winter comes fast after the autumn．But it is not very cold．It never(从不)snows in Shenzhen．I love the snow．I want to play with snow．
阅读短文，判断下列句子的对错。
