一个水桶正好装水18dm3，那么水桶的容积是18dm3．______．
一个水桶正好装水18dm3，那么水桶的容积是18dm3；
故答案为：正确
The tickets for the show have all been sold out. In other words, the tickets are not ____ now.
A．accurate
B．accessible
C．acceptable
D．available
简述β-内酰胺类药物抗菌的作用机制。
