Penny Lin

B(i): the picture shows that the diaphragm is in its dome shape. Therefore, we can conclude that the person is undergoing the process of exhalation.

C: When diaphragm is not functioning, it reduces the efficiency of gases exchange.

D(i): gas exchange releases carbon dioxide, which is toxic to our body, into the air.

D(ii): the alveoli are moist for gas to dissolved, they are one cell wall thick that leads to efficiency of gases exchange, and they have large surface area to allow more diffusion to take place.

B

90= 3x3x2x5

48=3x2x2x2x2

So, is it 2^4 x 3^3 ?

If not, please let me know the answer, thank u

Total internal reflection occurs in periscope.

A

B

b = 4.67

Each bulbs in Circuit C will light up with equal brightness as each of them have the same voltage. The total resistance in parallel circuit is reduced.

C

Cover the iron with silver paint ?