The lake

Question: Mary Jane is stranded on a deserted island in the middle of a huge and deep lake. She cannot swim and all she has is two strings that are each one foot long. All of the boats that she would be able to use are docked at the shore 4 miles away from her. 2 hours later, she is on the shore of the lake. How did she get across the lake?

Question: People see through me, but none pass through without killing me. I can be anywhere, and can be seen double or single. What am I?

Question: What can be broken but never forgotten?

Question: Which thing that comes once in a year, twice in a week?

Question: You are trying to get your chicken, fox, and wheat to the barn. However, the barn is on the other side of the river. You are on a boat and can only transport one animal or wheat at a time. You must choose carefully not to leave the wrong two together, though. It's either the fox will eat the chicken or the chicken will eat the wheat. How do you take each thing across safely?

Question: During what month do people sleep the least?