“道可道，非常道”是谁的说法：（）
A、孟子
B、老子
C、庄子
D、孔子
参考答案：B
This is Susan and that is Mary. _ my _ .
A．She's, friend
B．He's, friend
C．They're; friends
D．They're, friend
喷射砼前，应注意什么？
