(A) What’s the solution?

Your uncle who lives in Buldhana has an old scooter. It gives out a lot of smoke when it starts.

Ans: The solution is that the engine has to be serviced properly, and if after servicing the problem continues, it is best to buy a new scooter.

(B) Make a list

Make a list of vehicles that run on petrol or diesel.

Ans: Cars, trucks, vans, buses, tractors, etc. run on petrol or diesel. 

(C) Think and tell.

1. Waste water from a factory is let into a river. What harmful effects does it have on the people in the neighbourhood? 

Ans: When waste from a factory is dumped directly into a river without any treatment, it may cause serious problems for people living in the neighbourhood. The water of the entire river will get polluted, and people won’t have water to drink or use for agriculture. Also, both humans and animals in the nearby locality will have serious health problems.

2. How did the discovery of electricity make human life more comfortable?

Ans: The discovery of electricity has truly made human life more comfortable.

(i) We live in big buildings, but we can get water directly from taps because of the use of electric water pumps.

(ii) We also use electric lifts that help us climb big buildings without any physical work.

(iii) Electric trains make our transportation and commutes easy, cheaper, and with less pollution.

(D) Answer the following questions.

1. Which are the different vehicles that man has invented?

Ans: Man has invented vehicles like the motor car, bus, truck, scooter, train, and aeroplane.

2. What has to be done to set up new colonies?

Ans: To set up new colonies, the trees there have to be cut down.

3. Which diseases do mosquitoes spread? 

Ans: Mosquitoes spread diseases like malaria, dengue, filaria, and chikungunya.

4. How has taking more than one crop in a year affected groundwater?

Ans: The groundwater level is decreased by taking more than one crop in a year. Irrigation needs too much water for watering the crop, cleaning the seeds, etc. Different crops need different amounts of water to nourish. Direct extraction of groundwater in such quantities leads to a decreased level of groundwater.

(E) Fill in the blanks.

1. In summer, there is a …….  water in many villages and cities. 

Ans: shortage

2. A bullock or a male buffalo is used to turn the …….

Ans: Rahat-gadge

3. ……. is more intelligent than all other animals.

Ans: man

4. A mot is a large leather…..

Ans: bag

5. People leave their villages for the cities in search of ……

Ans: work

(F) Find out.

Obtain information about the following:

Using diesel and petrol sparingly

Saving water

Write down the information you obtain and share it with your classmates.

Ans: 

Using diesel and petrol sparingly:

If we overuse petrol and diesel, there is a probability that they will be exhausted in the near future because their reserves are limited on earth and are non-renewable resources. Also, the burning of these fuels causes air pollution or produces gases (like carbon dioxide) that are responsible for global warming. Due to these reasons, we must use substances like petrol and diesel sparingly and judiciously.

Saving water:

Clean, fresh water is a limited resource. With all the severe droughts happening in the world, the limited supply of fresh water is becoming one of our most precious resources. Every person on earth needs water to survive. Without it, many of us would get sick and even die. Hence, we should save water.