According to the image, the BC segment belongs to the melting process of the substance, during which the temperature remains unchanged, so the substance is crystal; It belongs to the boiling process of DE section;

If you stop heating the material, it will stop melting, indicating that the melting process needs to absorb heat, and the heat is always transferred from the flame with higher temperature to the water, indicating that the heat transfer is directional.

According to the image, the temperature of the substance is 50℃ in the 6th minute and 90℃ in the 8th minute.

∴Q suction =cm△t

=3× 103J/(kg？ ℃) × 200×10-3kg× (90℃-50℃)

=2.4× 104J

Q =m alcohol q alcohol

= 1.25× 10-3 kg× 3.0×107 joule/kg

=3.75× 104J

η=Q absorption q amplification × 100%

= 2.4× 104j 3.75× 104j× 100%

=64%

So the answer is: crystal; Absorption; Constant; Direction; 2.4× 104; 64%.