rr arrive 到達, 到來 [Card #3; 字卡第3張: 第2個單字, 字母組合發音 rr]
rr = /r/（2個相同子音在一起, 只發一個音）

Some more examples（更多例字）：array, arrange, carriage, carrot, parrot, carry, harry, parry, marry, merry, berry, cherry, ferry, terry, sherry, quarry, quarrel, harrow, yarrow, borrow, sorrow, arrow, sparrow, marrow, narrow, narrate, narrator, mirror, horror, error, terror, terrible, territory, terrific, arrogant, arrear, arrest, correct, corrode, corrupt, corroborate, correspond, corral, correlate, barrel, barren, barrier, barricade, errand, errata, erratic, irradiate, irrigate, irritate, serrate, ferret, embarrass, terrace, torrid, herring, guerrilla