1. Jehovah's Witnesses often go door to door to preach to strangers the Christian faith.2. My Christian group does field service every Wednesday evening in this neighborhood.3. I gave my neighbors a good witness about Bible truths. We talked for hours.
 preach field service witnesspreach 是非常籠統的字，指傳導任何看法或信念，用在傳道非常貼切
It gives the illusin that you've computed the entire answer immediately.