Explanation

"An honest person always speaks the truth."

• "Truth" is a noun and is the correct object of the verb "speaks".

• "True" is an adjective, and "truly" is an adverb — neither fits grammatically here.

Explanation

"Along" means following the length or edge of something, like the sea front.

So, the street runs along the sea front, following its direction.

Explanation

We use "on" for floors in a building (e.g., on the second floor).

So, "Her apartment is on the second floor" is correct.

Explanation

We commonly use "at home" to indicate someone's location.

So, "He is at home" is the correct phrase.

Explanation

The boat moves from one side to the other side of the river, so "across" is used.

"Across the river" means crossing over the river.

Explanation

• Comets: huge masses of snow and rocks that revolve around the Sun in orbits.
• Comets: have huge glowing tails.
• Halley's Comet was last seen in: 1986
• Halley's Comet will be next seen in: 2062

Explanation

An element with 7 valence electrons needs 1 more electron to complete its octet.

Therefore, its valency is 1, as it tends to gain 1 electron during bonding.

Explanation

When comparing two people, we use "more beautiful" (comparative form of "beautiful").

"Most beautiful" is used when comparing more than two.

Explanation

We use "in" to show that someone lives inside a place like a castle.

So, "The princess lives in the castle" is the correct usage.

Explanation