once; already; former; previously; ever; (past tense marker used before verb or clause)[cedict]
还
háiㄏㄞˊ
huánㄏㄨㄢˊ
also; in addition; more; still; else; still; yet; (not) yet[cedict]
pay back; return; surname Huan[cedict]
发生
fā shēngㄈㄚ ㄕㄥ
to happen; to occur; to take place; to break out[cedict]
过
guòㄍㄨㄛˋ
(experienced action marker); to cross; to go over; to pass (time); to celebrate (a holiday); to live; to get along; excessively; too-; surname Guo[cedict]
关系
guān xìㄍㄨㄢ ㄒㄧˋ
relation; relationship; to concern; to affect; to have to do with; guanxi[cedict]