Anything less dense than water will float, like oil. Anything more dense than water will sink, like rock.
When practicing an oral presentation, you can prepare by writing a draft and practice reading aloud what you are going to say before your oral presentation.
The Ammeter is used to detect and measure current or amperage. Also a more common tool now used is a multimeter that detects and measures voltage, current, and resistance.
Any questions please just ask. Thank you.