Questions

Adding the corresponding numbers in first and last figures gives the corresponding number in the middle figure.

i.e, 4 + 3 = 7

13 + 2 = 15

2 + 4 = 6

9 + 1 = 10

The header should have a minimum length of 20 bytes and can have a maximum length of 60 bytes.

The halogens make up group 17 in the periodic table.

They are five elements:

Chlorine (Cl)

Fluorine (F)

Bromine (B)

Iodine (I)

Astatine (At).

But astatine is not purely halogen as it is radioactive.

Desertification is a type of land degradation in which a relatively dry area of land becomes increasingly arid, typically losing its bodies of water as well as vegetation and wildlife.

Conversion of a grassland or an already arid land into a desert through indiscriminate human actions magnified by droughts.

Hence, forest improving to deserts is refers to desertification.