问题
选择题
In the advanced course students must take performance tests at monthly______.
A．gaps
B．intervals
C．length
D．distance
答案
答案：B
搜题请搜索小程序“爱下问搜题”
In the advanced course students must take performance tests at monthly______.
A．gaps
B．intervals
C．length
D．distance
答案：B