Light — Science STD 7 — Question

Why should sports persons and athletes drink more water?

The to and fro motion of an object from the position of rest is called a ___________.

State whether the following statement are true or false. Ships suffer a lot of damage though they are painted.

Plants prepare their food by a process called photosynthesis. Can we call photosynthesis is a chemical change? Explain.

Define a fibre.

Give the name of respiratory organs in following animals.

1. Fish.
2. Human being.

Fill in the Blank.
The bicycle tube ________ when it is overfilled with _________.

What would happen if it rains heavily in your town?

One day Sachin had gone to his uncle who lives in a village. He saw there a large number of people defecate in an open area because proper toilet facilities are not there. He wondered about the groundwater contamination, as he studied in his class that this act may cause water-borne diseases. He convinced village people to make toilets in order to avoid such an out break of water-borne diseases.
(i) Name two water-borne diseases.
(ii) What values are shown by Sachin?

List five products we get from forests.