Thomas was challenged in the Democratic primary by A.S. Mike Monroney in 1950 .
was challenged in 1950 by A.S. Mike Monroney in the Democratic Primary .
was challenged in 1950 by A.S. Mike Monroney in the Democratic Primary .
解释一下句子: Thomas was challenged in the Democratic primary by A.S. Mike Monroney in 1950 . 输出: