How to distinguish front nasal sounds from back nasal sounds?

, words with nasal sounds in front: real gold, people-oriented, colorful, people, poor people, hard work, gold and silver, salary, diligence, follow up, refreshing, confidence, patience, body and mind, dedication, cruelty, Clinic, minute hand, dust, introduction, imprint, treasure, pillow cover, gloomy, groan, pregnancy, caution, prudence, ginseng, earnest, forest, pinyin, verge, frequent, pity, neighbor, mere, audio, introduction, drink, character , benevolent, frame rate, Shenzhen, Tianjin, addiction, immersion, tight, close relatives, tree-lined, on the battlefield, encroachment, attentiveness, stealth, excitement, marriage, confidant, rare bird, appointment.

2. Single-front nasal words: provocation, chastity, consideration, measles, meticulousness, disaster relief, time, enthusiasm, early, reaching out, gentleman, what, aunt, even, hello, penetration, blade, river Bin, binbin, funeral, sideburns, utensils, annihilation, stinginess, rent, kilogram, sinews, banner, invasion, celery, beast, dormitory, chip, recruitment.

3. Words with all post-nasal sounds: life, equality, balance, smoothness, stability, tranquility, certificate, ping-pong, name, name-fighting, rectification of name, naming, renaming, correction, order, drunkenness, loneliness, exhortation , listen, wise, heroic spirit, elf, management, cold, ice, temperament, illness, illness, calm, tranquility, competition, disparity, vigilance, sobriety, capital, provincial capital, scenic spot, bottleneck, crystal clear, shrewd, determination, Heyday, victory, charter, journey, proof, rejoicing, ferocious, transpiration, rising, eagle, dragonfly, assessment, barracks, debut, once, lamp shadow, collision, hard support, ivy, intensive cultivation, Bingding, Pengcheng , surnamed Peng, alliance, initiation, awakening, dream, abundance, abundance, flattery, surname Feng, flattery, clarification, transcript, voice, steam, petition, show off, reputation, scenic spot, layer, disposition, disposition, parallel, condense Cheng, ringtone, sporadic, separately, please, softly, form, administration, promise, hazy, crazy, peak, sonorous, solemn, exquisite, blunt, sick, life, life, schedule, Qingming, scene, situation, situation, hospitality , statement, resignation, planet, star, stereotype, bible, mirror, behavior, lightness, conscription, steamed cake, rampage, lemon, screen, strong, plastic surgery, joy, well rope, suicide, bright light, echo, listening, affection.

4. Words with a single post-nasal sound: collapse, bandage, burst, jump, cook, pound, straw shed, flourish, maple leaf, honey, blockade, irony, stool, edge, stupefied, upright, Summary, rescue, make money, punishment, gallop, livestock, nephew, surplus, throw away, handle, apple, duckweed, lawn, whistle, living room, thunder, pavilion, court, thorns, hectare, fishy, ??baby girl, Flies, profits, cherry blossoms, mud puddles.