Explanation

Methane (CH₄) is produced during the anaerobic fermentation of biomass.

It is the main component of biogas.

It is widely used as a renewable energy source.

Explanation

The phrase "settle down" means to start living a stable and orderly life, often by getting married.

It's a common idiom used when someone is expected to stop moving around or partying and adopt a more settled lifestyle.

Explanation

Explanation

The correct sentence is: "You should have courage to ask an apology to him for your rudeness."

"To" is used for the person you're apologizing to, and "for" is used to indicate the reason or cause of the apology.

Explanation

In this sentence, the structure requires the present tense because the statement is a general truth.

The word "becomes" is the correct form.

Explanation

CFCs (Chlorofluorocarbons) are not produced by vehicles.

They are primarily released from refrigerants and industrial processes.

CO2, NO2, and CO are all pollutants emitted by vehicle exhaust.

Explanation

Pakistan and China often align their views in the United Nations (UN) on issues like sovereignty, non-interference, and global peace.

Both support each other’s positions on international matters such as Kashmir (Pakistan) and Taiwan (China) within the UN framework.

Explanation

"Unless you run fast" gives a condition for the main action (missing the bus).

Clauses that begin with unless, if, because, although are adverbial clauses (they modify verbs).

Explanation

"Because" is a subordinating conjunction, commonly used in complex sentences to show cause or reason.

It connects an independent clause with a dependent clause, e.g., She stayed home because she was sick.

Explanation

To find the LCM (Least Common Multiple) of 10, 16, and 25:

Prime factorization:

10 = 2 × 5

16 = 2⁴

25 = 5²

Now take the highest power of each prime:

2⁴ (from 16)

5² (from 25)

LCM = 2⁴ × 5² = 16 × 25 = 400