The Twins Days Festival,（ ）began in 1975, is the largest annual gathering of twins.
A.正确答案Bthat
B.which
C.who
D.when
The Twins Days Festival,（ ）began in 1975, is the largest annual gathering of twins.
The Twins Days Festival,（ ）began in 1975, is the largest annual gathering of twins.
A.正确答案Bthat
B.which
C.who
D.when
