The sun had already sunk below the horizon.

　　太陽(yáng)已沉下地平線。

　　His voice had sunk to a conspiratorial whisper.

　　他的聲音降到密謀低語(yǔ)的程度。

　　Pay increases have sunk to around seven percent.

　　工資增長(zhǎng)已下降到7％左右。