单项选择题
Koalas(考拉熊) use a range of sounds to communicate with one another（）relatively large distances.
A．in B．over C．by D．between
单项选择题 The mother didn't know who（）for the broken window.
单项选择题 （）the cause, they were able to propose to a remedy.
单项选择题 Never（）Josh met such a complicated situation.
