Winter and women

Question: In the middle of winter, a woman is found dead in her bed, with multiple stab wounds in the stomach. Soaked into the sheets is a massive amount of blood, along with blood drops on the carpet. On the side table beside her bed, there is a glass full of water mixed with blood. What was the murder weapon, where is it now, and how was she killed?

Question: One day a man broke his leg. When he was sent home from the hospital he had to use a wheelchair. The doctors told him he could not go up stairs. When the man got home he realized he had stairs to get into his house on both sides. The man saw his neighbor, the doctor who x-rayed him at the hospital, getting out or her car. The man asked "can you carry me up the stairs?" The woman replied "no." Why?

Question: During what month do people sleep the least?

Question: When is 99 more than 100?

Question: You have a glass of water that looks about half full. How can you tell, only using the glass of water itself, if the glass is half full or not?

The glass is a right cylinder.

Question: What goes through towns and over hills, but never moves?