Excellent work. I am sure you will easily pass English paper.

(f) Is this his half – brother?
(f) Is he his half-brother?

I think Answer is;

Is he his cousin ?
Half-Brother means cousin,
I think i have read it, in Exploring the world of English. (Please Correct me)

And:

(a) The lake free zed rapidly.
(a) The lake froze rapidly.

Answer Is: The lake has frozen rapidly

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كُلُّ نَفْسٍ ذَآئِقَةُ الْمَوْتِ - Every Soul Must Have The Taste Of Death