Choose the most appropriate option to fill in blank no. 2.

In the following passage, some words have been deleted. Read the passage carefully and select the most appropriate option to fill in each blank.
Sniffer dog Tucker uses (1)________ nose to help researchers find out why a killer whale population off the northwest coast of the United States is (2)________ the decline. He searches for whale faeces floating on the surface of the water, which are then collected for examination. He is one of the elite team members of detection dogs used by scientists studying a (3)________ of species including right whales and killer whales.
Conservation canines are fast becoming indispensable tools for biologists according to Aimee Hurt, associate director and co-founder of Working Dogs for Conservation, (4)________ in Three Forks, Montana.
Over the last few years, though, so many new conservation dog projects have sprung up that Hurt can no (5)________ keep track of them all. Her organisation’s dogs and their handlers are fully booked to assist field researchers into 2012.

Show answer & explanation

Correct answer: D

Explanation

The correct answer is option 4 i.e. on

Context: The sentence talks about the killer whale population and whether it is declining. The blank should indicate the condition or state affecting the population.

Meaning of the words:

on – indicates a condition, state, or effect (e.g., “on the rise,” “on the decline”)
off – indicates separation or distance
after – indicates time sequence
at – indicates location or specific point

Correct word:

Reason: The standard phrase in English is “on the decline” to describe something decreasing. Other options like off, after, or at do not make sense in this context.

Final Sentence: Sniffer dog Tucker uses its nose to help researchers find out why a killer whale population off the northwest coast of the United States is on the decline.

Hence, the chosen option will be correct

SSC MTS 2024 PYQ — Question 88