Explanation

In solar furnaces, concave mirrors are used for converging the sun's rays.

concept:

Concave mirrors reflect and focus incoming light rays (parallel) at a point, called the focus point.

Depending on the distance of an object from the reflecting surface, different types of images are formed.

Explanation

Sparked by the arrest of Rosa Parks on 1 December 1955,

the Montgomery bus boycott was a 13-month mass protest that ended with the U.S. Supreme Court ruling that segregation on public buses is unconstitutional.

Date: December 5, 1955 – December 20, 1956 

Explanation

The average length of pregnancy is 9 months 240 days and 40 weeks.

**

concept

Pregnancy is counted from the first day of your last menstrual period.

This means an extra 2 weeks are counted at the beginning of your pregnancy when you aren't actually pregnant.

So pregnancy lasts 10 months (40 weeks)

—not 9 months—because of these extra weeks.

Explanation

Carbon Microphone is a type of microphone, a transducer that converts sound to an electrical audio signal.

Explanation

We do not allow people to smoke in the kitchen.

the above sentence is a "simple sentence" and does not require any helping word 

"To smoke" is best to keep the meaning of the original sentence

Explanation

Carbon Dioxide is heavier than oxygen

so we might expect every CO2 molecule to sink below a layer of oxygen molecules.

"concept"

The Molecular weight and therefore the density (at the same temperature and pressure) of CO2 is only marginally higher than the average density of air.

Explanation

Active: She had made a big mistake.

Passive: A big mistake had been made by her.

Active Voice Formula: Subject + had + V3+ object.

Passive Voice Formula: Object + had+ been + V3 + (By + subject)

Explanation

Explanation

Explanation

He took the course in order to get a better job.

اس نے بہتر ملازمت حاصل کرنے کے لیے کورس کیا۔

In order to get is best to keep the meaning of the original sentence.

To get is an irregular verb.

SH4-8-2023