Exercise 1 solution

Example answer (yours will differ):
Check first: push a finger 5 cm into each. Do not water by habit.
Lettuce (raised bed): raised beds drain fast. Check every day or two; water in the morning at the base when the top 5 cm is dry. A good soak (a full can over the bed) rather than a sprinkle. Keep it steady so the plants do not bolt or turn bitter.
Carrots: water deeply about twice in the week if the finger test is dry, aiming to keep moisture even. Avoid long dry spells followed by a flood, which can split roots.
Tomatoes in pots: pots dry fastest. Check daily; in warm weather water every day, in the morning, until water starts to come from the drainage holes. Keep it even to avoid split fruit.
Extra: mulch the lettuce and carrot bed, and stand the pots together in partial shade at midday if they dry out too fast.