"Margaret had ambivalent feelings about attending the concert. She knew she’d enjoy the music, but she didn’t really want to go out in the rainy weather." What does ambivalent mean?

"Marine biologists are scientists who study sea creatures". What does "marine" mean?

"I couldn't see through the dingy window because it was so dirty". What does "dingy" mean?

"Jen thought the diamond was authentic, but I knew it was fake". What does "authentic" mean?

"His teacher told Ben to avoid trite, overused expressions in his writing". What does "trite" mean?

"Before the surgery, the nurse ensured that all of the instruments were sterilized and completely cleaned." What does sterilized mean?

"The last book we read was thrilling, but this book is rather prosaic". What does "prosaic" mean?

"The weatherman said that a behemoth, powerful storm is approaching our area". What does "behemoth" mean?

"Unlike my brother, who is very messy, my room is always tidy". What does tidy mean?

"The pudgy baby panda bear looked chubby and round." What does pudgy mean?

"Ali was hoping to be the hero in the school play, but instead she was chosen to be the villain". What does "villian" mean?

"Tammy knew she should feel happy about the last day of school, but she actually felt quite lugubrious when she thought about the three months that were coming up." What does lugubrious mean?