1. The hot, dry, painful winds blowing between Delhi and Patna are called Loo.

2. Flows in the plains of northern India and Pakistan in the months of May and June.

3. Heat waves can reach temperatures of up to 45 degrees Celsius, and can last for several hours.

1. The distance covered by the first train between Bombay and Thane in 1853 was approximately 34 km.

2. This train was pulled by three steam engines named Sahib, Sultan and Sindh. The train had 14 coaches and was carrying about 400 people.

After considering the following statements regarding the main causes of extreme cold in North India during the cold season, the correct statements have been identified.

1. States like Punjab, Haryana and Rajasthan, being far away from the moderating influence of sea, experience continental climate.

2. The snowfall in the nearby Himalayan ranges creates a cold wave situation.

3. Around February, the cold winds coming from the Caspian Sea and Turkmenistan bring a cold wave along with frost and fog over the northwestern parts of India.

1. Humus is found in the topmost layer of soil (A-horizon).

2. Humus is a black or brown colored substance which makes the soil fertile.

3. It is an important source of nutrients for plants, and it helps the soil absorb water and air.

4. There are many ways to promote humus, including-

- Leaving crop residues in the field

- Using livestock manure

- making compost