慢性阻塞性肺疾病的主要特征是（）
A.大气道阻塞
B.气流阻塞
C.双肺哮鸣音
D.桶状胸
E.胸片示肺野透亮度增加
参考答案：B
Look，read and write.（根据下面每句话的意思和图片的提示，在空格中填上适当的单词，
使句子完整）
1. This is my ______.That is your ______.
2. — What's in the classroom?
— Look, four _______and six _______
3. It's 3 :00. It's time for _______ class.
4. — What colour is the _______? — It's red.
5. — What _______ is it? — It's_______ o'clock.
（）是对数据重新进行编码，以减少所需存储空间的通用术语。
A.数据编码
B.数据展开
C.数据压缩
D.数据计算
.That is your ______
.
and six _______
.
? — It's red.
.