Puzzles

How many words of three letters or more can you make from the letters in this grid? There are at least 200 words, including one nine letter word.

1. Which London landmark is open when it's closed, and closed when it is open?
2. I have keys, but no lock. You can use me to enter, but you cannot go in. I have a space that you can never fill. What am I?
3. What is once in a minute, twice in a moment, but never in a thousand years?

Word Square

age, agent, aim, air, airmen, akin, amen, anger, anime, ant, ante, are, argent, ark, arm, arming, art, ate, ear, earn, eat, eating, eking, emigrant, emir, emit, enigma, era, gain, gait, gaiter, game, gamer, gamin, garment, garnet, gate, gear, gem, gent, germ, get, giant, gin, git, gnat, grain, gram, granite, grant, grate, great, grim, grime, grin, grit, image, inert, ingrate, ink, inker, inmate, intake, inter, irate, ire, irk, item, keg, ken, kern, kin, kina, king, kit, kite, knit, magnet, main, make, maker, making, man, mane, mange, manger, mare, margin, marine, mark, market, marketing, marking, mart, martin, mat, mate, mater, mating, mean, meant, meat, men, merit, met, meting, mien, migrant, migrate, mike, minaret, mine, miner, mink, mint, mirage, mire, mite, mitre, nag, name, nark, near, neat, net, nit, nitre, rag, rage, ragtime, raiment, rain, rake,  raking, ram, ramekin, ran, rang, range, rank, rant, rat, rate, rating, ream, regain, reign, rein, remain, remaking, remit, rent, ret, retag, retain, retaking, retina, rig, rim, rime, ring, rink, rite, tag, take, taken, taking, tame, tamer, taming, tan, tang, tank, tanker, tar, tare, tarn, tea, teak, team, teaming, tear, tearing, ten, term, tern, tie, tier, tiger, time, timer, tin, tine, tinge, tinker, tire, train, tram, trek, triage, trim

Three simple questions

1: Tower Bridge - when the lifting part of the bridge is open for ships it is closed for cars.

2: I am a computer or typewriter keyboard

3: The letter 'm'.