Could someone help? And quick cause im getting ready for bed!!

The ph level of a blueberry is 3.1 what is the hydrogen-ion concentration [h+] for the blueberry

What is the missing reason in the proof? segment addition congruent segments theorem transitive property of equality subtraction property of equality?

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap