The brave officer ---------- the time bomb

Analyze the question: The sentence needs a verb in the past tense that means to make a bomb harmless by removing its fuse or detonator. This is a question on spelling and on words that are easily confused.

Explain the concept: Two similar-looking words are commonly mixed up:

• Defuse means to remove the fuse of a bomb so it cannot explode. It also means to calm a tense situation. The prefix de- means "remove", so defuse is "remove the fuse".
• Diffuse means to spread out or scatter, as in "diffuse light" or "the gas diffused through the room". It can also describe something wordy and unclear.

Solution:

1. The officer is dealing with a time bomb, so the meaning needed is "made it harmless". That is defuse.
2. The past tense is defused.
3. Check the options: • A. diffused is a real word, but it means "spread out", which does not fit a bomb. • B. druse is a cluster of crystals in a rock cavity, which is irrelevant here. • C. defused is correct in both spelling and meaning. • D. difused is a misspelling and is not a word.

Answer: The brave officer defused the time bomb. The correct option is C.

Tip: Think "DE-fuse = DE-activate". A bomb has a fuse, and you take it away. For diffuse, remember the double f in "spread out" and "differ", since both suggest things moving apart.