异型耐火砖设计时，两个面的夹角一般应（）。
A.小于30°
B.不小于30°
C.不大于20°
D.越小越好
参考答案：B
Last summer, I went back to my hometown, the neighbors and the houses that I used to be familiar with were gone．
A．only finding
B．only to find
C．to find
D．found
热制冷食菜肴在烹制过程中，______采用勾芡的方法。
A．不能
B．必须
C．少数
D．多数
