There is an error in each sentence that has been underlined. Correct the error in the following sentences.
We waited for a hour before the bus finally arrived.
an hour
The guide insisted on an uniform jacket for the group's safety during the trek.
a uniform
Mount K2 is a second highest peak in the world.
the second
A Ganga is a sacred river in India, known for its cultural importance.
The Ganga
Challenges are faced with courage and determination by a brave.
the brave
A North Star has guided travellers for centuries.
The North Star
Explanation
(i) 'An' is used before 'hour' because it begins with a vowel sound (the 'h' is silent). (ii) 'A' is used before 'uniform' because it begins with a consonant sound (the 'u' sounds like 'you'). (iii) 'The' is used with ordinal numbers like 'second', 'first', 'third'. (iv) 'The' is used with names of rivers as they are unique geographical features. (v) 'The' is used before adjectives used as nouns referring to a class of people ('the brave' means 'brave people'). (vi) 'The' is used with unique celestial bodies like the North Star.