Bird migration
Bird migration is a fascinating phenomenon observed in various species worldwide. It refers to the seasonal movement of birds from one region to another, typically covering long distances. Migration occurs in (1)___________ to changing environmental conditions such as temperature, food availability and breeding opportunities. Some species of migrating birds travel (2)___________ distances each year.
The Arctic tern is the seabird which holds the record for the longest migration route, travelling from its breeding grounds in the Arctic to its wintering grounds in the Antarctic. This round-trip journey (3)___________ over 44,000 miles, as these birds do not follow a straight course but take advantage of prevailing winds.
Ruby-throated hummingbirds, found in North America, are tiny creatures which (4)___________ a migration covering approximately 2,000 miles. What makes this journey impressive is that they navigate across the whole Gulf of Mexico in a non-stop flight.
However, the bar-tailed godwit, a wading bird which breeds in the Arctic, has the longest non-stop migration route of any bird species. (5)___________ some individuals fly over 7,000 miles from Alaska to New Zealand across the Pacific Ocean in a single flight that can last up to eight days.
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Correct Answer: C
Why this is correct: response is correct because 'in response to' is a fixed phrase meaning 'reacting to'. Birds migrate in response to changes like temperature and food.
Tips: Memory trick: nature does not send letters, so it is not a reply. Birds react, so it is 'in response to'.
Why the other options are wrong:
- A: reply gives 'in reply to', which means answering a message or letter. This is a Thematic Trap - it is about communication, not reacting to nature.
- B: answer gives 'in answer to', which is used for questions, not for reacting to weather and food changes.
Key Vocabulary:
- in response to = reacting to
- in reply to = answering a message
Correct Answer: A
Why this is correct: remarkable means 'surprisingly great, worth noticing'. 'Remarkable distances' fits the amazing lengths that some birds travel each year.
Tips: Memory trick: re-MARK-able - something you would mark or point at because it stands out. Remarkable distances stand out.
Why the other options are wrong:
- B: excellent means 'very good in quality'. Distances are not good or bad in quality, so 'excellent distances' does not collocate.
- C: marvellous means 'wonderful and delightful'. It is about how pleasing something is, not how big a distance is, so it sounds odd here.
Key Vocabulary:
- remarkable = surprisingly great = worth noticing
- marvellous = wonderful, delightful
Correct Answer: B
Why this is correct: comprises means 'is made up of' or 'adds up to'. It takes a direct object with no preposition, so 'the journey comprises over 44,000 miles' works cleanly.
Tips: Memory trick: 'comprises' already contains the meaning of 'is made up of', so it needs no 'of'. 'Consists' always drags 'of' along.
Why the other options are wrong:
- A: consists needs 'of' - you say 'consists of'. This is a Structural Trap - 'consists over 44,000 miles' is missing that little word 'of'.
- C: conveys means 'communicates or carries a message'. That is the wrong meaning for a total number of miles.
Key Vocabulary:
- comprise = be made up of (no 'of')
- consist of (always needs 'of')
Correct Answer: B
Why this is correct: undertake means 'take on' or 'begin a big task'. 'Undertake a migration' is a natural pairing, meaning the birds set out on that long journey.
Tips: Memory trick: under-TAKE - you take a big job onto your shoulders. Birds undertake a huge journey.
Why the other options are wrong:
- A: commit needs 'to' - you commit to something. This is a Structural Trap - 'commit a migration' does not follow the right pattern.
- C: endeavour means 'try hard', and it takes 'to do' - 'endeavour to fly'. This is a Structural Trap - 'endeavour a migration' does not fit.
Key Vocabulary:
- undertake = take on = begin a big task
- endeavour to do something (needs 'to')
Correct Answer: A
Why this is correct: Incredibly means 'amazingly' or 'hard to believe'. It sits at the start to show wonder that tiny birds fly over 7,000 miles in one go.
Tips: Memory trick: in-CREDIBLE - not credible, almost too amazing to believe. Incredibly is the word of wonder.
Why the other options are wrong:
- B: Impossibly means 'in a way that cannot happen'. But the birds do fly it, so 'impossibly' contradicts the facts.
- C: Indefinitely means 'for an unlimited time with no end'. The flight does end, after about eight days, so it does not fit.
Key Vocabulary:
- incredibly = amazingly = hard to believe
- indefinitely = with no end in time
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