投票【とうひょう】
voting, ballot, poll, vote
投資【とうし】
investment
投機【とうき】
speculation, venture, stockjobbing, gambling (on stocks)
投書【とうしょ】
letter (e.g. of complaint), letter to the editor, letter from a reader, contribution (to a newspaper, magazine, etc.)
投稿【とうこう】
contribution (to a newspaper, magazine, etc.), submission, post (on a blog, social media, etc.)
投じる【とうじる】
to throw, to cast (e.g. vote, light, shadow), to devote oneself (e.g. to a cause), to invest, to put in, to administer (medicine), to give, to surrender, to take advantage of, to make full use of, to fit well with, to match with, to be in tune with, to stay (at a lodging)
投射【とうしゃ】
projection (of an image)
投影【とうえい】
projection
投げる【なげる】
to throw, to hurl, to fling, to toss, to cast, to give up, to abandon, to throw away, to cast (a glance, shadow, doubt, etc.)