FOUR USES OF CONCAVE MIRROR:Satellite dishes,headlights of a car, telescopes used for astronomical studies, and shaving mirrors because of there curved and reflective surface.
FIVE USES OF LENSES: Camera lens ,microscopes ,magnifying glass,eyeglasses,projector
Answer:
a) wet marble , dry marble, newspaper, and towel
Answer:

east of south
Explanation:
Given:
- distance of the person form the initial position,

- direction of the person from the initial position,
north of east
- distance supposed to travel form the initial position,

- direction supposed to travel from the initial position, due North
<u>Now refer the schematic for visualization of situation:</u>

...............(1)

.................(2)
<u>Now the direction of the desired position with respect to south:</u>


east of south
<u>Now the distance from the current position to the desired position:</u>



Answer: *The inner planet that has two moons is Mars * the only planet in the Solar System with clockwise rotation is Venus * The surface of Mercury is covered with ancient magma ( which is similar to the spews of volcanoes on Earth as well) * The planet that is closest to Earth is Mercury * Venus has more volcanoes than any other planet * Earth's moon formed when a(n) can sometimes be called the Big Splash or can be called the Theia impact (Luna the moon formed from the ejecta of the collision between the Proto- Earth and Mars sized planet) * Mars is called the red planet because it's soil contains the element iron oxide ( which is the compound that gives blood and rust hue)
Explanation: Hope this helped :)