___ is not related to gases.

Fire : Burn :: Water : ?

$$\begin{gathered} (4x - 7)2 = ? \\ \end{gathered}$$

X does 25% of a work in 20 days. Y joins X and they together finish the remaining work in 15 days. Y alone can do the whole work in ___ days.

____ are twin prime numbers.

Find the missing (?) in the series.

AB, CE, FI, ?, OT

In human body, vertebrae are part of ___.

The Land Ports Authority of India works under which Union Ministry?