下列细胞壁各层中最厚的层是（）。
A.复合胞间层
B.次生壁
C.S1层
D.S2层
参考答案：D
Correct the mistakes. 找出错误并在横线上改正。
1. This is mine scarf.
2. She put on her dress.
3. Today is monday.
4. This is pair of pants.
5. These pyjamas are too just right.
下列房地产转移或转让行为中，应当征收土地增值税的是( )。
A．直系亲属继承的房屋B．有偿转让的合作建房C．房地产评估增值D．无偿赠与直系亲属的房屋
