What distinguishes an insect from a crustacean?

Which of the following is not a macromolecule?

If $R$ is the set of all real numbers and $f: R-\{2\} \rightarrow R$ is defined by $f(x)=\frac{2+x}{2-x}$ for $x \in R-\{2\}$,find the range of $f(x)$.

The $EN$ (Electronegativity) of element $A$ is $E_1$ and its $IP$ (Ionization Potential) is $E_2$. Hence,its $EA$ (Electron Affinity) will be:

$A$ liquid of mass $m$ and specific heat $c$ is heated to a temperature of $2T$. Another liquid of mass $m/2$ and specific heat $2c$ is heated to a temperature of $T$. If these two liquids are mixed,what will be the final temperature of the mixture?

If $A$ and $B$ are square matrices of order $3$, $A$ is non-singular, and $AB = O$, then $B$ is a: