by sheer [a curious] coincidence
まったくの［不思議な］偶然の一致で
by simple declaration
単に宣言するだけで
by single [postal] ballot
単記無記名［郵便］投票で
by some calculations
ある計算では
by some fortuity
何かの偶然で
by some freak of fate [fortune, chance]
偶然のいたずらで
by [on] special [kind] permission of ...
…の特別の［寛大な］計らいで
by spells
交替で
by statute
法令によって
by stealth
人目を忍んで，こっそりと
