Question

subject verb aggrement. (1) the famous juggler and conjurer ____ too unwell to perform. and why

Answer 1

The correct answer is were. There may be many other ones

Hope this might help u

Answer 2

The famous juggler and conjurer is too unwell to perform.

Because the subject in this phrase is singular and refers to the same individual, who is a well-known juggler and conjurer, is/was should be the correct response.