Relative pronouns/adverbs

Dad drives my grandparents, _______ car is old and unreliable.

To address this invitation, I should use:

The friend ______________ usually helps me before a Physics quiz is sick at the moment.

The bank has extended our loan, ______________ which we are thankful.

My dad’s desk, ______________ he works at when at home, used to belong to his father.

I remember the time ______________ we would hang out every weekend.

We visited the museum, ______ exhibits showcased various artifacts from ancient civilizations.

We would like to know with ______________ you plan to attend the celebration dinner.

The park area ______________ we sit is closed.

The book, __________ I borrowed from the library last week, turned out to be an exciting mystery novel.