歌曲《让爱住我家》中唱道：“我爱我家，弟弟爸爸妈妈……让爱天天住你家，让爱天天住我家，不分日夜，秋冬春夏，全心全意爱我们的家。让爱天天住你家，让爱天天住我家，充满快乐，拥有平安，让爱永远住我家。”可见，歌曲的词作者认为家庭中最重要的是（   ）

如图所示，在垂直纸面向里的匀强磁场的边界上，有两个质量和电量均相同的正、负离子（不计重力），从点O以相同的速度先后射入磁场中，入射方向与边界成θ角，则关于正、负离子在磁场中的运动，下列说法错误的是（   ）

大气污染表现在(　　)

读我国四大地理区域图，完成下列问题。

阅读短文，下列问题

A

    It's two weeks before Christmas in England and Mrs. Smith is very busy. She buys a lot of Christmas cards to send to her friends and to her husband's friends. She puts them on the table in the room. Then, when her husband comes home from work, she says to him, “These are the Christmas cards for your friends. Could you please write the cards and I cook supper?”

    Mr. Smith doesn't say anything and walks into his study. After a while, he comes with a box full of Christmas cards. He puts them on the table and says, “They are from last year. I forgot(忘记) to send them.”