“无把握”的英语？

不打无把握之仗.Fight no battle you are not sure of winning.不打无准备之仗, 不打无把握之仗.Fight no battle unprepared; fight no battle you are not sure of winning.事实上, 这个方法是很费事 、 很困难而且是无把握的.In practice, the method is tedious, difficult, and u...