Explanation

Add and Added show a change from present to past tense.

Say and Said also represent present to past tense, matching the same pattern.

Explanation

Equisetum is commonly called horse-tail due to its brush-like appearance.

It belongs to Pteridophytes.

It is a living fossil.

It is found near wetlands.

Explanation

Hirudinaria is a genus of leeches, which are segmented worms.

Leeches belong to the phylum Annelida, known for segmented bodies.

Explanation

"Hour" begins with a silent h, so it sounds like it starts with a vowel.

Therefore, we use "an" before "hour" — "150 miles an hour."

Explanation

After 3 half-lives, the mass remaining is calculated as:

Mass remaining = Initial mass / 2³

= 160 μg / 8

= 20 μg

Explanation

Dull means سست

Brilliant means شاندار

Interesting means دلچسپ

Explanation

Parasites are classified as ectoparasites (living on the surface) and endoparasites (living inside the host).

Both types represent different forms of parasitic symbiosis with their hosts.

Explanation

Aldehydes and ketones contain a polar carbonyl group (C=O) which is susceptible to nucleophilic attack.

They commonly undergo nucleophilic addition reactions, a key feature of their reactivity.

Explanation

Blood type O has no A or B antigens on the surface of red blood cells.

That's why type O is known as the universal donor in blood transfusion.

Explanation

The direction of the induced emf is predicted by Lenz's Law.

It states that the induced emf always acts to oppose the change causing it.