If I _____ you, I would not do that.

• A. am
• B. was
• C. were (Answer)
• D. had been

In conditional type 2 (unreal present), use 'were' for all persons after 'if'.

He is working hard _____ he may pass the exam.

• A. because
• B. so that (Answer)
• C. although
• D. unless

'So that' expresses purpose. He works hard with the purpose of passing the exam.

The police _____ after the thief.

• A. ran (Answer)
• B. run
• C. running
• D. runs

The sentence is in simple past tense. 'Police' takes plural verbs, and 'ran' is past tense of 'run'.

She is not only intelligent _____ also hardworking.

• A. and
• B. but (Answer)
• C. or
• D. nor

'Not only...but also' is the correct correlative conjunction pair.

I have been waiting _____ an hour.

• A. since
• B. from
• C. for (Answer)
• D. during

'For' is used with a duration of time (an hour). 'Since' is used with a specific point.

He apologised _____ being late to the meeting.

• A. about
• B. for (Answer)
• C. of
• D. at

'Apologise for' is the correct collocation.

The work must be completed _____ Friday.

• A. until
• B. since
• C. by (Answer)
• D. for

'By' means not later than. 'Until' means up to a point in time (continuing action).

Neither of the two boys _____ done the work.

• A. have
• B. has (Answer)
• C. had
• D. are

'Neither' takes a singular verb.

He is too weak _____ carry the heavy luggage.

• A. to (Answer)
• B. for
• C. that
• D. and

'Too + adjective + to + infinitive' shows that something is not possible because of excess.

She told me _____ not to worry.

• A. for
• B. that
• C. about
• D. no word needed (Answer)

'Told me not to worry' is correct. With 'tell + object + not to', no joining word is needed.