下列环境中,铁制自行车最容易生锈的是( )
A:寒冷干燥的东北地区
B:炎热干燥的沙漠地区
C:寒冷多雪的高原地区
D:炎热多雨的南方地区
将装有甲烷和氯气混合气体的三个集气瓶,用玻璃片把瓶口盖好后,分别作如下处理,各有怎样的现象发生.
看图,阅读短文,判断正误。
Tommy is a boy. He is apupil. He is a short and thin. He is ten. He gets up early every morning. He gets up at half past six. He brushes his teeth at a quarter to seven in the morning. He goes to school at half past seven in the morning.
读图,完成下列问题。