在20℃下能溶于17。5％氢氧化钠溶液中的纤维素为（）。
A、α—纤维素
B、β—纤维素
C、γ—纤维素
D、半纤维素
参考答案：B, C, D
— My teacher says she's cancelling the class play. I just can't understand.
— ______.You were looking forward to it. [ ]
A. It doesn't matter
B. It's very unwise of her
C. Don't worry about it
D. You must be disappointed
翻译句子。
1. 我的拖鞋坏了，你能帮我修理吗？
My slippers is are ______. Cold you ______ me ______them?
2. 王先生正带着他们参观我们学校。
Mr. Wang is ______ ______ ______ our school.
3. 你们都在，让我们开始吧！
You ______ ______ here. ______ begin!
4. 相册里是什么？让我看看！
What are ______ ______ ______ ______? Let me ______ a ______!
5. 妈妈，我的另一只袜子呢？
Mum, where is ______ ______ sock of mine?
