sign in

签到；签收

sidle, siege, sienna, sierra, siesta, sieve, sift, sifter, sigh, sight, sight-read, sight-reading, sight-screen (also screen), sighted, sighting, sightless, sights, sightseeing, sightseer, sign, sign language, sign on, signal, signal-box, signaller (US signaler), signally, signalman, signatory, signature, signature tune (also theme tune), signet, signet ring, significance, significant, significantly, signification, signify, signor, signpost, Sikh,