通常条件下，塑料（）时能采用挤压成形。
A.任何情况
B.固体状态
C.粘流性
D.不确定
参考答案：C
工程上广泛采用的培养基灭菌方法有间歇灭菌和（）。
When Steven suddenly remembered that he had left his mobile in the office, the train was already ________.
A．on the go
B．on the rise
C．on the run
D．on the move
