What I Have Learned A. Fill in the blank spaces to complete what you have learned about the lesson. I have learned that one of the earliest tools that human beings invented was the (1) The basic unit of length for metric is the (2) - Approximately one (1) inch is about (3). cm. The metric unit used for (4) The determining the mass/weight is the (5) of an object is the amount of matter it contains. The (6)__ on the other hand, is the pull of gravity on the object. The mass of the paper clip is about __(7)_g. The metric unit used Our water consumptions are measured in for determining the volume __(8). (10)__ is measured by the rotation of the earth on its axis. A_ (11) (9) is used to determine the measure of an angle in degrees. Temperature commonly used units are_(12)_ for the Metric system and (13) for the English system, the base SI unit for temperature is the (14)_. A (15) is a ratio of two measurements having different units of measurements.​