501.We'd better discuss everything ____ before we work out the plan.
A.in detail
B.in general
C.on purpose
D.on time
502.This shop will be closed for repairs ______ further notice.
A.with
B.until
C.for
D.at
501.答案是A;考查介词短语在具体语境中的作用。句意:我们最好先详细地讨论好一切，然后再制定计划。In detail 详细地；in general 一般而言，总的来说,大体上；on purpose 故意地;on time 准时。根据句意选A。
502.答案是B;until further notice为习惯搭配，意为:直到另行通知。
