紧密相联

closely interrelated / intimately related

tight / strict / close at hand / near / urgent / tense / hard up / short of money / to tighten

inseparably close

secret / confidential / close / thick / dense

each other / one another / mutually / fret on the neck of a pipa 琵琶[pi2 pa5] (a fret on the soundboard is called a 品[pin3])

appearance / portrait / picture / government minister / (physics) phase / (literary) to appraise (esp. by scrutinizing physical features) / to read sb's fortune (by physiognomy, palmistry etc)

to interact / interrelated

to ally / to unite / to join / (poetry) antithetical couplet