Statement $\mathrm{I}$ Doldrums is a calm belt between $5°\mathrm{N}$ and $5°\mathrm{S}$ of the equator.

Statement $\mathrm{II}$ The Sun rays strike almost vertically over the equator throughout the year.

Which of the following statement(s) is/are correct?

Which of the following statements about tornadoes are correct?

Tornadoes usually spin:
$1$. Anti-clockwise in the Northern hemisphere.
$2$. Clockwise in the Southern hemisphere.
$3$. Clockwise in the Northern hemisphere.
$4$. Anti-clockwise in the Southern hemisphere.

Select the correct answer using the codes given below.

Which of the following statement(s) is/are correct?
$1$. Air close to the Earth's surface is heavier.
$2$. Air close to the Earth's surface contains a larger quantity of water vapour and dust particles.

Select the correct answer using the codes given below.

Which of the following are the results of El-Nino?
$1$. Reduction in the amount of planktons which further reduces the number of fish in the sea.
$2$. Irregularities in the evaporation of seawater.
$3$. Distortion of equatorial atmospheric circulation.

Select the correct answer using the codes given below.