Here are the best answers for each question based on common English usage:

**12.** Don't stand **D. in front of** the TV! I'm trying to watch this programme.

**13.** You should never stand **B. under** a tree when it is raining.

**14.** My father has a car, and this is my **A. father's car**.

**15.** She always goes to school **B. by** foot.

**16.** My father is only home **A. on** weekends.

**17.** Nam is reading books **C. in** the library now.

**18.** My town house is **A. in** the city centre.

**19.** Do you play **A. usually** football with your classmates after school? (The correct positioning of "usually" should be "Do you usually play football...")

**20.** I'm having two houses and three cars. I'm feeling rich! (This sentence is already correct; however, it could be simplified to "I have...")

**21.** He can’t speak on the phone because he **B. has** a shower.

**22.** Don’t disturb me! I **A. am reading** a good book.

**23.** My brother sometimes **A. plays** the guitar in a band.

**24.** When Susie usually **B. does** her homework?

**25.** We **are cycling** to school at the moment.

Feel free to ask if you'd like further clarification on any of these answers!