问题
选择题
The Australian boy has a good _____ of Chinese and can communicate with others freely.
A．request
B．command
C．demand
D．usage
答案
答案：B
题目分析：此处request要求；command命令；demand要求； usage用法。这里have a command of意为：掌握。故选B。句意：这位澳大利亚男孩掌握了汉语并能用汉语和别人自由的交流。