he has been working so hard . __________ he could answer such a difficult question.
_______ are the days when girls were looked down upon.
The missing boys were last seen _______ near the river.
— I’m afraid the date for the interview doesn’t suit me. — _______, we can make it another day.
_______, his idea was accepted by all the people at the meeting.
_______ about wild plants that they decided to make a trip to Madagascar for further research.