某厂生产固体化工产品共计250桶,按规定应至少从()桶取样制备后测定。
A、10桶
B、19桶
C、25桶
D、250桶
参考答案:B
If you are ____ about Australian cities, just read the book written by Dr Johnson. [ ]
A. interested
B. anxious
C. upset
D. curious
蒸汽机械式雾化器是如何工作的?有何特点?