Which of the following is a transparent tissue?

Lithium shows similarities to magnesium in its chemical behaviour because

If the number average molecular weight and weight average molecular weight of a polymer are $40000$ and $60000$ respectively,the polydispersity index of the polymer will be

The part of the nephron involved in the active reabsorption of sodium is

The value of $\sqrt{(\log_{0.5} 4)^2}$ is