Problem: Does "The Song dynasty reestablished unity around 960." answer the question "When did the Song dynasty reestablish unity around?"

A: yes

Problem: Does "The goal was to promote year-round trade and a year-round navy.:11 Pursuit of this goal brought the emerging Russian state into conflict with the Ukrainian Cossacks and then with the Tatars of the Crimean Khanate and Circassians." answer the question "Who did Russia first have issues with when moving towards the warmer ports in the Black Sea?"

A: yes

Problem: Does "Thermal mass is any material that can be used to store heatheat from the Sun in the case of solar energy." answer the question "What is thermal mass?"

A:
yes