(A) What’s the solution ?
Your uncle who lives in Buldhana has an old scooter. It gives out a lot of smoke when it is started.
Ans. The solution to this is either the engine has to be serviced properly. But if after servicing if the problem continues, then it is best to buy new scooter.
(B) Make a list. Make a list of vehicles that run on petrol or diesel.
Ans. Car, Truck, Van, Bus, Tractor, etc.
(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 let into a river directly without any treatment then if 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 of use for agriculture. Also both the humans and animals in the near by 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 without any work in our home 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 transport and commuting easy, cheaper with lesser 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, trains and aeroplanes.
2. What has to be done to set up new colonies ?
Ans. To set up new colonies the trees there had 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. Taking more than one crop in a year had resulted in decrease in the amount of available groundwater.
(E) Fill in the blanks.
1. In summer, there is a shortage of water in many villages and cities.
2. A bullock or a male buffalo is used to turn the rahat-gadge .
3. Man is more intelligent than all other animals.
4. A mot is a large leather bag .
5. People leave their villages for the cities in search of employment .