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Sentence analysis
9Spans
Sentence
Span Details
長い
long (distance, length); long (time); protracted; prolongedi-adjective
期間
period; term; intervalnoun
に
direction, time, indirect object, or target markergrammar
わたっ
cross over; go across; extend; span; cover; range-> 渡るgodan verb
て
connective te-formgrammar
研究
research; study; investigationnoun, suru verb
を
object markergrammar
続け
continue; keep doing; keep up; continue to ...; keep on ...-> 続けるichidan verb, auxiliary
ました。
polite pastgrammar