有效性供应链主要体现供应链的( )。
A．价值功能
B．实物功能
C．机械功能
D．服务功能
参考答案：B
根据读音先写出多音字，再组词。
shuā ( ) shuà ( ) dān ( ) shàn ( )
mú ( ) mó ( ) jiān ( ) jiàn ( )
píng ( ) bǐng ( ) sǎo ( ) sào ( )
Tom was _____ the queue when I saw him. [ ]
A. at the head of
B. at head of
C. on the head of
D. around
