Thethieftookawaythewoman’swalletwithout________.
A、beingseenA
without 是介词，其后的动词必须用动名词形式。根据句意，此句需要用被动形式，所以答案是 A 。
Johnsonwas________unknownbeforerunningforthepresidency.
If payment is not received, legal action will be our only ________.
Younger children are curious ________ how things work ，and many of them want to take apart everything within their reach.
Thisisanimportantproblem_______toofewsocialscientistshaveresearched.
Thereply,whenitfinallycame,was________thenegative.
