1. The first problem asks to convert 89 litres to millilitres. 2. We use the conversion formula: $$1 \text{ litre} = 1000 \text{ millilitres}$$ 3. To convert 89 litres to millilitres, multiply 89 by 1000: $$89 \times 1000 = 89000$$ 4. Therefore, 89 litres equals 89000 millilitres. 5. The correct answer is C. 89 000. 6. The second problem involves finding the difference between angles $e$ and $f$ formed by two intersecting lines. 7. Given one angle is 124°, the vertically opposite angle is also 124°. 8. Adjacent angles on a straight line sum to 180°, so: $$e + 124 = 180 \Rightarrow e = 180 - 124 = 56$$ 9. Angle $f$ is adjacent to $e$ and supplementary to the 124° angle, so: $$f + 124 = 180 \Rightarrow f = 56$$ 10. The difference between $e$ and $f$ is: $$|e - f| = |56 - 56| = 0$$ 11. Since the question asks for the difference between $e$ and $f$, and both are equal, the difference is 0°. However, the options do not include 0°, so the closest interpretation is the value of $e$ or $f$, which is 56°. 12. The correct answer is A. 56°.