ক. A computer is ... (a/an/the) ultra-wonder invention.
উ. an

খ. I am confident ... (about/of/with) his success.
উ. about

গ. 'Without working hard, you will fail'- transform the sentence into compound.
উ. Work hard, or you will fail.

ঘ. 'They thanked us'- change the sentence to direct speech.
উ. They said to us, "Thank you".

ঙ. 'He is better than you' - write down the positive form of the sentence.
উ. You are not as good as he is.

চ. Write the passive voice of the sentence - 'Who stole the pen?'
উ. By whom was the pen stolen?