It is five years _____his father worked here.
A:from
B:before
C:when
D:since
①竦峙____
A.sǒng B.sóng
②蛙声____
A.wa B.wā
③
A.zì B.cì
④鸣蝉____
A.chán B.cháng
—_________. I'm full(饱的).