a, His foot was injured .He managed to walk to the nearest hospital.
⇒ Although my foot was injured, I managed to walk to the nearest hospital .
b,Although Tom was a poor student, he studied very well.
⇒ In spite of being a poor student, Tom studied very well.
c,The distance from Ha Noi to Hai Phong is about 100 km
⇒ It is about 100 km from Ha Noi to Hai Phong.
d,There were traffic jams in this street during rush hours, but now there aren't.
⇒ There used to be traffic jams in street during rush hours, but now there aren't .