1.1.2 Exam. Semester Exam How could you best increase the mechanical efficiency of a screwdriver for
using it to open a can of paint?
A. Make it out of material that is very strong so that more of the input
work is changed into useful output work.
B. Make the handle smooth and slippery to reduce friction with the
user's gloves.
O C. Make it out of material that bends easily so that less of the input
work is changed into useful output work.
O D. Make the handle thin to reduce the user's ability to grip it and apply
an input force

Factors that can increase mutation rates a. high temps b. low temps c. food additives d. uv rays

Read this summary of a scientific theory: "cells are the most basic structural and functional units of life. all living organisms are made up of one or more cells. all cells that are alive in the world today came from pre-existing cells." which of the following would require this theory to be modified? -a.) a survey finds that a majority of people believe viruses carry out the basic processes of life. -b.) a prominent scientist says she feels strongly that one day the theory will be challenged by life on other planets. -c.) the dna of unicellular and multi-cellular organisms is shown to have many fundamental similarities. -d.) scientific observations show that microscopic organisms living in the deep ocean are not made up of cells.

The most effective way to provide children with safety messages is to