一も二も無く[ichimonimonaku] unhesitatingly
一言二言[hitokotofutakoto] a word or two
一石二鳥[issekinichou] killing two birds with one stone
一二に及ばず[ichininioyobazu] right away
一姫二太郎[ichihimenitarou] It's good to have a girl first and then a boy

うり二つ[urifutatsu] as alike as two melons (two peas in a pod)
黄道十二宮[koudoujuunikyuu] twelve signs of the zodiac
二度[futatabi] again
最小二乗法[saishounijouhou] least-squares method
三十二分音符[sanjuunibuonpu] 32nd note

ぶっ通し[buttooshi] continuous
イタルタス通信[itarutasutsuushin] ITAR-TASS News Agency
インタファクス通信[intafakusutsuushin] Interfax news agency
シリアル通信[shiriarutsuushin] serial communication
タス通信[tasutsuushin] TASS News Agency

データ通信[deetatsuushin] data communication
パソコン通信[pasokontsuushin] personal computer communication
パラレル通信[pararerutsuushin] parallel communication
ビジネススクール入学共通試験[bijinesusukuurunyuugakukyoutsuushiken] business school entrance test
ロイター通信[roitaatsuushin] Reuters (news agency)