下列词语划线的字，每对读音都不相同的是（ ）

She was put under house arrest two years ago but remained a powerful ________ in last year’s election.

In the beginning，the man refused to say anything about the lost car，but he had toadmit________it because of the solid proofs.[ ]

irst ______ to the market, these new products intheir company enjoyed a great success

Jackie is only six years old __________ he can play soccer very well.