My sister enjoys taking photographs of flowers in the spring. Error: B - to take → taking

Video games can be addictive. Don't spend too much time on it. Error: A - on → in

It takes me about fifteen minutes to go to school by bicycle. No error.

It's easier to find a job in the city than in the country. Error: D - than → than it is

Remember to lock the doors before going out, won't you? No error.