Answer:

1. A.

The horizontal axis represents the values corresponding to each data value. Here, the data values are the number of students who like a particular color represented on the vertical axis. The scale shows the value of 1 unit on the horizontal axis.

B. Generally speaking, scientists use the metric system, which is a decimal system used internationally for weights and measures, for reporting scientific results. The most commonly used SI units for measuring different variables are: Mass: kilogram. Time: seconds

2. A. the line of figures or coordinates that are arranged from left to right along the bottom of a graph or map: The vertical axis represents value; the horizontal axis represents time.

B. Generally speaking, scientists use the metric system, which is a decimal system used internationally for weights and measures, for reporting scientific results. The most commonly used SI units for measuring different variables are: Mass: kilogram. Time: seconds

3.Actually…all the things in the practical world are difficult to measure.For instance consider measuring the length of the bank of a pond,when yoll measure then you will simply come up with some answer like 11 metres or so.but when yoll observe the bank of the pond carefully yoll find a lot of irregularities and after considering all the “visible” irregularities as your part of measurement yoll come up with some different measurement that will obviously be more than what you got earlier…say 15 metre…and as we can never consider all the irregularities in practical world,we can never measure anything…