问题
选择题
________it have been the failure to pick up directions from the ground control that caused the air crash?[ ]
A．Must
B．Could
C．Would
D．Should
答案
答案：B
搜题请搜索小程序“爱下问搜题”
________it have been the failure to pick up directions from the ground control that caused the air crash?[ ]
A．Must
B．Could
C．Would
D．Should
答案：B
覆盖关系