1. Nobody but Jane___________ the secret.
A. know B. knows
C. have known D. is known
答：B。
2. All but one ______ here just now.
A. is B. was C. has been D. were
答：D。不定代词all，some，theres to等做主语时，谓语根据情况而定，若指可敷意义，谓语用复数；若指不可数意义或抽象意义时谓语用单数。此题中all指人，“大家，所有的人”；若指抽象事物，谓语应用单数。如：All is clear。一切都清楚了。
3. Not only I but also Jane and Mary ______ tired of having one examination after an other.
A. is B. are C. am D. be
答：B。
4. A library with five thousand books _____ to the nation as a gift.
A. is offered B. has offered
C. are offered D. have offered
答：A。见第一题解析。
5. When and where to build the new factory______ yet.
A. is not decided B. are not decided
C. has not decided D. have not decided
答：A。从句、不定式、动名词做主语时，谓语动词常用单数形式，如where we’ll hold the meeting has not been decided yet。虽然是两个疑问词并列，但指开会这一件事，故用单数谓浯。若指两件事时，谓语应用复数。如What he did and what he said were different.。他所做的和他所说的是不一致的。从句做主语时，谓语一般用单数形式，但当what从句做主语时应根据其意思来决定。
如：
What we need are some engineers. 我们需要的是一些工程师。
What we need is an English interpreter. 我们需要一位英语翻译。