What does a bomb calorimeter measure?

Which of the following is an incorrect pair?

At what temperature is the density of water maximum (in $^\circ \text{C}$)?

Which of the following is the correct match?

Given below are two statements:
Statement $I$: $A$ protein is imagined as a line,the left end represented by the first amino acid ($N$-terminal) and the right end represented by the last amino acid ($C$-terminal).
Statement $II$: Adult human haemoglobin consists of $4$ subunits (two subunits of $\alpha$ type and two subunits of $\beta$ type).
In the light of the above statements,choose the correct answer from the options given below:

The nitrogen content of urea is: (in $\%$)