Choose the correct option to fill in the blank.
We must leave now________ it is getting dark.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → since
Complete sentence: We must leave now since it is getting dark. "It is getting dark" is the reason why "we must leave now", so the blank needs a word of reason: since.
| Option | Meaning and use | Example |
|---|---|---|
| (1) provided that | Provided that introduces a condition (only if). The darkness is a fact that gives the reason, not a condition for leaving. | You may go out provided that you finish your homework first. |
| (2) as soon as | As soon as introduces time (immediately when). It clashes with "now" and gives no reason. | Call me as soon as you reach home. |
| (3) therefore | Therefore introduces a result. It would make the darkness the result of our leaving, which turns the meaning round. It is an adverb that links two sentences (usually after a semicolon), not a conjunction that joins a clause in this way. | It was very late; therefore, we took a taxi. |
| (4) since (answer) | Since, because and as join a clause that gives the reason for the action in the main clause. Clue: "it is getting dark" explains why we must leave, so a word of reason is needed. | Since it was raining heavily, the match was called off. |