December 25th is Christmas Day. In most countries it is the most important day in the year. All the people come back to their homes to have the day with their parents or their children. On Christmas Day bells ring everywhere. The ringing bells tell people Christmas is coming. People sing and dance day and night. They have a good time.

Most families buy a Christmas tree for their children. And there are some presents hanging from the tree here and there. People also put presents in children’s stockings. In many places, Father Christmas himself brings presents to them. He is a kind man and in red clothes. There is a big bag on his back. In it there are a lot of presents.

Christmas is also a day when people enjoy all kinds of food. But some poor people have no homes and have no food to eat. They die of cold and hunger(饥饿)on Christmas Day.

根据以上短文内容，请判断下列句子的正误，正确的用“T”，错误的用“F”。

小题1:Christmas is a very important day in some countries in a year.

小题2:Many people have a good time on Christmas Day.

小题3:Father Christmas wears red clothes.

小题4:There are a lot of Christmas trees in Father Christmas’bag.

小题5:Some poor people die on Christmas Day because they have no homes and no food to eat.

现在的教室作为标准化考场，都安装了如图所示的电子监控器，其主要由光学系统和光电转换系统两部分组成。光学系统收集监控区域内的景物信息，经光电转换系统转换成电信号并输送到监控中心。其中光学系统的工作原理是利用（   ）

A．平面镜成实像

B．平面镜成虚像

C．凸透镜成实像

D．凸透镜成虚像