Answer:
Spoilage microbes produce acid
Explanation:
When food becomes spoiled or is unprotected, bacteria will invade the food. These types of bacteria are called spoilage bacteria. The bacteria will multiply by consuming the nutrients from the food and grows very rapidly. In certain conditions, the invading bacteria will produce acids that protects them and creates a barrier for other microbes. This acid is what gives spoiled food a sour taste.
Advantages of using solar energy are pollution-free, noise-free, on installation it produces free energy, clean and renewable. Disadvantages include high cost, energy dependent on sunlight exposure, power stations are expensive to build and devices powered by solar energy cannot be used at night
23 from mom,
23 from dad,
all together 46! :3
I'm pretty sure it is refraction <span />