Meaning: "practicing" means doing something again to get better.

Wrong options:

• practiceing: It adds an extra "e". Write "practicing". Only the exact spelling gets the mark.

Correct answer: collecting

Explanation: Listen again to "have been collecting audio". The phrase needs an action word that ends in ing.

Meaning: "collecting" means gathering or recording things.

Wrong options:

• colleting: It leaves out the "c". The right spelling is "collecting". Every letter must be correct to get the mark.
• collect: "collect" is missing the ending. The speaker says "collecting", with "ing" at the end.

Correct answer: energetic

Explanation: Here you hear "produced by the energetic particles". You need a describing word for the particles.

Meaning: "energetic" means full of energy or very active.

Wrong options:

• energitic: It has "i" where the word has "e". Write "energetic". Only the exact spelling gets the mark.
• energies: "energies" is a close word, but it ends in "ies". The speaker says "energetic", which ends in "etic".

Correct answer: microphones

Explanation: The speaker says "three ground-based microphones allowed". After ground-based you need a thing word, more than one, so do not forget s.

Meaning: "microphones" means devices that record or pick up sound.

Wrong options:

• microhpones: Two letters are in the wrong order. Write "microphones". Only the exact spelling gets the mark.
• microphone: "microphone" has no "s" at the end. The speaker says "microphones", so write the "s".

Correct answer: phenomenon

Explanation: You hear "understanding of the phenomenon". After "the" you need a word for a thing, ends in on.

Meaning: "phenomenon" means an event or thing that happens and can be studied.

Wrong options:

• phenomenom: It has "m" where the word has "n". The right spelling is "phenomenon". Every letter must be correct to get the mark.
• phenomena: "phenomena" is a close word, but it ends in "a". The speaker says "phenomenon", which ends in "on".