健康, けんこう
1. health
NA-adjective
2. healthy, sound, fit, wholesome
煙草をすうことは健康に悪い。
だ
Auxiliary verb, copula, See である, See です, plain copula
be, is
た, だ
Auxiliary verb, だ after certain verb forms; indicates past or completed action
1. did, (have) done
indicates mild imperative
2. (please) do