a leap in the
问题描述：
a leap in the
答
a leap in the dark
[英]ə li:p in ðə dɑ:k [美]e lip ɪn ði dɑrk
结果不可预料的行动;轻举妄动;冒险行动;冒昧之举
[例句]The experiment was a leap in the dark.
这项实验实在是冒险.