Sure, let's go through each question and identify the underlined part that needs correction:

**Question 1:**
If Lucia **had been** here now, she **would find out** the truth **about** her **uncle’s** accident.
- **Correction:** A (should be "were here now" to match the present conditional)

**Question 2:**
**If** a student **takes a course** on Computer Science, it will **take** him four years **doing** the course.
- **Correction:** D (should be "to do" instead of "doing")

**Question 3:**
**Unless** it **did not rain**, Peter **would pay** us **a visit**.
- **Correction:** B (should be "rained" instead of "did not rain")

**Question 4:**
If **had I known** you **were** **in** financial difficulty, I **would have helped** you.
- **Correction:** A (should be "I had known")

**Question 5:**
**If** I **had knew** the time **when** the match started, I **would have told** you.
- **Correction:** B (should be "had known")

**Question 6:**
If she **had finished** **the work**, she can **go** **home**.
- **Correction:** C (should be "could go")

**Question 7:**
If I **had spoken** more **confident** at the interview, they **would have offered** me **the** job.
- **Correction:** B (should be "confidently")

**Question 8:**
**If** we **had had** a map, we **would not** **be lost** yesterday.
- **Correction:** D (should be "have been lost")

**Question 9:**
**Had I known** **Alice’s** address, I **would write** **to her**.
- **Correction:** C (should be "would have written")

**Question 10:**
If I **had realized** **that** the **traffic lights** were red, I **would stop**.
- **Correction:** D (should be "would have stopped")

**Question 11:**
If **had you sent** the application form **to that company**, you **would have** **been offered** a job.
- **Correction:** A (should be "you had sent")

**Question 12:**
He **spends** money **carelessly** **as if** he **was** a millionaire.
- **Correction:** D (should be "were")

**Question 13:**
**Unless** you **work** harder, you **will be sack** because of your **laziness**.
- **Correction:** C (should be "will be sacked")

**Question 14:**
**Unless** there **had been** the **heavy** storm, the climbers **will** not have died.
- **Correction:** D (should be "would not have died")

**Question 15:**
She **has found** that nobody **can help** her if she **did not try** her best **to do** it herself.
- **Correction:** C (should be "does not try")

**Question 16:**
If we **will reduce** the speed of **population growth**, there will be **less** pressure **on** the earth.
- **Correction:** A (should be "reduce")

**Question 17:**
**If** we leave **a bowl of** water **under** the sun, it **will evaporate**.
- **Correction:** No correction needed.

**Question 18:**
**If** we continue **to use** fuels at the current rate, we **would** soon have **to face** a fuel crisis.
- **Correction:** C (should be "will")

**Question 19:**
If she **bought** that house **now**, she **ran** out **of** money.
- **Correction:** B (should be "buys")

**Question 20:**
**What** **you would do** if you **could** speak French **well**?
- **Correction:** B (should be "would you do")

**Question 21:**
**If I had** my mobile yesterday, **I could have contacted** and **informed you** about the last-minute **cancellation of the seminar**.
- **Correction:** A (should be "had had")

**Question 22:**
**If you had** studied **hard**, you **wouldn't** **failed** the exam.
- **Correction:** D (should be "have failed")

**Question 23:**
If I **hadn't been** too **late for** the exam, I **might be** **allowed to enter** the examination room.
- **Correction:** C (should be "might have been")

**Question 24:**
**I would** **have enroll on** an online course **if I had had** **enough money**.
- **Correction:** B (should be "have enrolled in")

**Question 25:**
**We might** have **gone to** the Science Fair **if we** **knew about it** happened.
- **Correction:** D (should be "had known about it")

**Question 26:**
If we **had drop** school **so early**, we **wouldn't** have **had enough** knowledge of the school subjects.
- **Correction:** A (should be "had dropped")

**Question 27:**
If you **had come** to class **last week**, you **might have join** in the discussion **on air pollution**.
- **Correction:** C (should be "might have joined")

**Question 28:**
If **I had listened** to **my parents**, I **wouldn't** **have been** in so much trouble now.
- **Correction:** D (should be "wouldn't be")

**Question 29:**
I **don't know** your phone number. If **I had known** it, I **would** **have called** you last night.
- **Correction:** No correction needed.

**Question 30:**
If I **have studied** English **earlier**, I **could** **have read** this book several years ago.
- **Correction:** A (should be "had studied")

**Question 31:**
If a meteor **hadn't** **struck the Earth**, the dinosaurs **didn't become** **extinct**.
- **Correction:** C (should be "wouldn't have become")

**Question 32:**
If they **had win** the lottery **last summer**, they **would have** **bought** a new car.
- **Correction:** A (should be "had won")

**Question 33:**
If I **had known** he **is not** at home, I **wouldn’t have gone** all the way **to** his house.
- **Correction:** B (should be "was not")

**Question 34:**
If I **had known** that the road **were flooded**, I **would** never **have taken** that way.
- **Correction:** B (should be "was flooded")

**Question 35:**
If I **were** you, I **will go** to **the dentist’s** and have the tooth **checked**.
- **Correction:** B (should be "would go")

These corrections should help ensure the sentences are grammatically correct.