At room temp attire a mixture of sand and water can be separated by

Two friends at different locations want to communicate with each other by sending low energy signals. which of the following methods can they use to communicate? a) produce x-rays using colliding electrons and send them to radios, which capture sound b) send messages using infrared radiation, which travel in the form of waves c) send radio waves through intervening media like radio and television d) produce sound waves using microwaves from heated objects

Which of the dna typing techniques do you think you would choose if you had to analyze a dna sample? why?

Design techniques and materials that reduce the negative environmental impact of a structure are referred to as