补货操作注意事项有（）。
A、首先要掌握缺货情况
B、补货前要清洁货架
C、补货时要注意先进先出原则
D、补货后清理场地
参考答案：A, B, C, D
Read and choose. （读句子，选择与句子相匹配的图片）
( )1. Excuse me, where is the washroom?
( )2. Listen! Students are having the music class now.
( )3. I often play ping-pong in the gym.
( )4. Do you often go to the library?
结合肺段模式图，选出右肺上叶的组成()
A．A
B．A+B
C．A+B+C
D．A+B+C+D
E．A+B+C+D+E
