Answer:
The boldface numbers on this beam are grams and the tick marks between the boldface numbers indicate tenths of grams. To find the mass of the object on the pan, simple add the numbers from the three beams. As with a ruler, it is possible to read the front scale to the nearest half tick mark.
One half-life after a radioactive isotope is incorporated into a rock there will be only half of the original radioactive parent atoms remaining and an equal number of daughter atoms will have been produced.
The U.S. history would be narrower than the width of the line.
It is Choice B "by drinking water and other liquids"
