Earth, Moon, and the Sun — Science STD 7 — Question

Choose the odd one out from each group and give reasons. oesophagus, small intestine, large intestine, rectum.

What are combustible substances? Give two examples.

Name the process by which heat transfer in air.

State the relation between radius of curvature and focal length of spherical mirrors.

What is simple pendulum?

Which part of the digestive canal is involved in:
Killing of bacteria _____________.

Name the plant that forms the lowest layer in forest.

Predict the following change can be reversed or not be reversed. If you are not sure, you may write that down. Why are you not sure about these?
Making idlis from a batter

How do insects breathe?

State the consequence when one food chain is disturbed in an ecosystem.