The correct answers are as follows:
1. He took the rain and stormy weather as an <u><em>ominous</em></u> sign that his day would not go well.
The word, ominous, is an adjective that describes and foreshadows something dark, worrying, or a "bad" that is expected to happen. In the sentence, someone is interpreting rainy and stormy weather as a sign or dark omen that foreshadows a bad day. Another way to use ominous in a sentence could be: "Her ominous prophecy came true."
2. She did not qualify for the Tennis Finals, so she was in a <u><em>melancholy</em></u> mood the whole day.
Melancholy describes a mood or state of being, where an individual feels down, depressed and disheartened. In the sentence provided, someone feels melancholic, or sad and disheartened when she did not qualify for her Tennis finals. Melancholy can also be used in a sentence as follows: "The mood at the funeral can only be described as melancholy."
3. The frog had a sleek body that twisted in a <u><em>sinuous</em></u> way as it leaped.
Sinuous can be defined as having several curves, twists and turns, or moving in a lithe and agile manner. A snake and cat can be described as moving in a lithe and sinuous way. In this instance, a frog is described as moving, by twisting it's body, by turning and twisting agilely.
4. He had to apologize for using <u><em>profane </em></u>language; they were threatening to kick him out of camp.
Profane can be defined as something that is offensive, disrespectful and unholy. Swear words are commonly referred to as "profanity". In this instance, someone was using disrespectful and offensive language, due to which, he could have been kicked out of camp.