Explanation

It is estimated that around 14 muscles are involved when a person smiles.

Major muscles include the zygomaticus major and minor, which lift the corners of the mouth.

Explanation

The present perfect tense (has + past participle) needs "sewn" (past participle of "sew").

"She has sewn her dress" is grammatically correct.

Explanation

An electrical impulse causes the cardiac cell's resting potential to convert into an action potential.

This action potential leads to contraction of heart muscle cells, enabling the heart to beat.

Explanation

The multiplicative inverse of a number is its reciprocal.

For -1/9, the reciprocal is -9/1 or simply -9.

Explanation

In Pakistan, federal and provincial governments are formed after general elections, held every 5 years.

These elections determine the members of the National Assembly and Provincial Assemblies, who then elect the Prime Minister and Chief Ministers.

Explanation

Inertia is the property of an object to resist any change in its state of rest or uniform motion.

It is described in Newton’s First Law of Motion, also called the Law of Inertia.

Explanation

Total length of lace = 19 m 61 cm = 19.61 m

Length used = 8 m 89 cm = 8.89 m

Remaining length = Total length - Length used

Remaining length = 19.61 m - 8.89 m

Remaining length = 10.72 m

Explanation

This is the easiest test I've taken.

"Easiest" is the correct superlative form of the adjective "easy" (easy → easier → easiest).

The structure follows the rule: "the + superlative adjective" (e.g., the tallest, the smartest, the easiest).

Explanation

The average is calculated by dividing the sum of quantities by the number of quantities. Therefore, the number of quantities can be found by dividing the sum by the average.

Number of quantities = Sum / Average

Number of quantities = 5200 / 650

Number of quantities = 8

Explanation

A number divisible by both 2 and 5 is automatically divisible by their LCM = 10.

For example, 20 ÷ 2 = 10, 20 ÷ 5 = 4, and 20 ÷ 10 = 2.