I don't want to be disturbed, so don't give me a call unless it's something important.

Conjunctions: A conjunctions is a word used to join or connect words, groups of words, phrases, clauses or sentences.

Subordinating Conjunction:  They are used to connect two groups of words or two statements, one of which is dependent on the other. Some subordinating conjunctions are though / although, since, after, till / until, as, because, before, if, while, when, whether, lest, as if, as soon as, as long as, as though, than,etc.

Conjunctions  A conjunction is a word or phrase that connects words, phrases, clauses, and sentences together. The word and is a commonly used example of a conjunction. Here are two examples of how we can use a conjunction like and in both a simple and complex way:

• The flower is yellow and white. (connects two adjectives)
• The flower is yellow, and it has a particular smell. (connects two sentences)

Conjunctions are useful in writing and speech to connect related ideas together, and they help us make our sentences shorter, less repetitive, or less confusing.

Subordinating Conjunction:

They are used to connect two groups of words or two statements, one of which is dependent on the other. Some subordinating conjunctions are though / although, since, after, till / until, as, because, before, if, while, when, whether, lest, as if, as soon as, as long as, as though, than,etc.

Subordinating conjunctions join the main (or independent) and subordinate (or dependent) clauses together.

In the question : -

1. He finished his work as fast as possible ________ that he could leave early. In this sentence, the correct subordinating conjunction that can be placed in the blank part is So as it is used to show "in order to" .

2. Don't do anything ______ I come back. In this sentence, the correct subordinating conjunction that can be placed in the blank part is Until as it is used to show "up to the time that" .

3. _________ I came in the room, everyone looked at me. In this sentence, the correct subordinating conjunction that can be placed in the blank part is When as it is used to show "at that time" .

Thus , the Correct Option is D , which is so , until , when .

Conjunctions  : - A  conjunction is a word or phrase that connects words, phrases, clauses, and sentences together. The word and is a commonly used example of a conjunction. Here are two examples of how we can use a conjunction like and in both a simple and complex way:

• The flower is yellow and white. (connects two adjectives)
• The flower is yellow, and it has a particular smell. (connects two sentences)

Conjunctions are useful in writing and speech to connect related ideas together, and they help us make our sentences shorter, less repetitive, or less confusing.

Subordinating Conjunction: They are used to connect two groups of words or two statements, one of which is dependent on the other. Some subordinating conjunctions are though / although, since, after, till / until, as, because, before, if, while, when, whether, lest, as if, as soon as, as long as, as though, than,etc.

They join a Subordinate Clause to a Principal Clause and help in the formation of complex sentences.

Example : - Stay here till I come back. Here , till is used to connect two groups of words or two statements, one of which is dependent on the other .

In the question : -

1. Keep your hand on the wound ___________ the bleeding stops. In this sentence , until is the correct subordinating conjunction that can be placed in the blank part as it means  "up to the time that" .

2. I will succeed _______ you will fail. In this sentence , whereas is the correct subordinating conjunction that can be placed in the blank part as it is used for showing a fact that is different .

3. ________ you're going out, I'm staying in. In this sentence , since is the correct subordinating conjunction that can be placed in the blank part as it means from a particular time in the past until a later time in the past or until now .

Thus , the Correct Option is B , which is Until , whereas , since .