发型制作中（）的作用是增加发量，使头发连接在一起。
参考答案：打毛
You can only be sure of_________ you have at present; you cannot be sure of something _____ you might get in the future.
A．that; what
B．what; /
C．which; that
D．/; that
LNG系统汽化和调压总成由（）组成。
A、总成底架
B、汽化器
C、电磁阀
D、稳压阀
