the genitive case of group nouns(短语的所有格)

Cliff’s and Al’s/Cliff and Al’s

【问】 Cliff’s and Al’s car broke down again，but luckily they knew how to fix it. (TOEFL)

我看不出Cliff’s and Al’s car有什么错误。

【答】 Cliff’s and Al’s与Cliff and Al’s的意思是不一样的。前者表示Cliff与Al各有的事物，而后者表示Cliff与Al共有的事物。从句意来看，显然是Cliff与Al共有一个car。

请做下面的英语试题：

1. The lady over there is____.

A. Jane and Mary mother B. Jane and Mary’s mother

C. Jane’s and Mary’s mother D. Jane’s and Mary mother

2. The doctor checked up both John’s____hearts.

A. mother-in-law’s and his brother-in-law’s

B. mother’s-in-law and his brother’s-in-law

C. mother-in-law’ and his brother-in-law’ s

D. mother-in-law and his brother-in-law’s

3. “Why should I try Larry and Kevin’s pickles?”

“Because____the best.”

A. his are B. theirs are

C. theirs is D. his is(TOEFL)