从事食品生产、食品流通、餐饮服务,应当依法取得食品生产许可、食品流通许可、餐饮服务许可。
参考答案:对
She had just finished her homework_____her mother asked her to practice playing the piano yesterday. [ ]
A. when
B. while
C. after
D. since
如图BZ26所示该安全标志表示的意思是()。
A.注意安全
B.当心辐射
C.当心爆炸
D.当心腐蚀