For complex editing and manipulation of PDF files, you will need to purchase Adobe Acrobat. If you just want to be able to open or export existing files as PDF files, then there are free options. Acrobat Reader, Foxit Reader, or Windows Reader App are a few free options for viewing .pdf files. You can create a document in a word processor like Word, or Google Docs and save it as .pdf file, but further manipulation of that PDF will not be possible without Acrobat. Open Adobe Acrobat and press Tools > Create PDF. This is where you start when importing files to turn into a PDF or starting a new PDF from scratch. There are a number of import options to choose from, including importing a single or multiple files, a scanned file, a webpage, or the contents of your clipboard. Adobe limits its file support to Microsoft Office (2007 and later) or OpenOffice filetypes, as well as basic text (.txt, .rtf), image files, or other adobe products. Selecting a file will create a PDF copy of that file in the same location on your computer as the original file. With the file now opened, press "Edit PDF" and select a highlighted box of text. You can either type out the changes you want or utilize the options in the Format section. Press "Edit PDF" and select any highlighted image. Use the options in the Objects section to manipulate the image.
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One-sentence summary -- Determine how you will be using PDF files. Create a PDF file from an existing file. Edit text in the imported file. Edit images in the imported file.

Q: It's easy to see the principles of enthalpy in action with a simple experiment. To make sure that the reaction in your experiment will take place without any foreign contamination, clean and sterilize the container that you plan to use. Scientists use special closed containers called calorimeters to measure enthalpy, but you can achieve reasonable results with any small glass jar or flask. Regardless of the container you use, fill it with clean, room-temperature tap water. You'll also want to conduct the reaction somewhere indoors with a cool temperature. For this experiment, you'll want a fairly small container. We'll be testing the enthalpy-altering effects of Alka-Seltzer on water, so the less water used, the more obvious the temperature change will be. Grab a thermometer and set it in the container so that the temperature-reading end sits below the water level. Take a temperature reading of the water for our purposes, the temperature of the water will represent T1, the initial temperature of the reaction. Let's say that we measure the temperature of the water and find that it's exactly 10 degrees C. In a few steps, we'll use this sample temperature reading to demonstrate the principals of enthalpy. When you're ready to start the experiment, drop a single Alka-Seltzer tablet into the water. You should notice it immediately start to bubble and fizz. As the tablet dissolves in the water, it breaks down into the chemicals bicarbonate (HCO3-) and citric acid (which reacts in the form of hydrogen ions, H+). These chemicals react to form water and carbon dioxide gas in the reaction 3HCO3 + 3H+ 3H2O + 3CO2. Monitor the reaction as it proceeds the Alka-Seltzer tablet should gradually dissolve. As soon as the tablet finishes its reaction (or seems to have slowed to a crawl), measure the temperature again. The water should be slightly colder than before. If it's warmer, the experiment may have been affected by an outside force (like, for instance, if the room you're in is especially warm). For our example experiment, let's say that the temperature of the water is 8 degrees C after the tablet has finished fizzing. In an ideal experiment, when you add the Alka-Seltzer tablet to the water, it forms water and carbon dioxide gas (the latter of which can be observed as fizzing bubbles) and causes the temperature of the water to drop. From this information, we would expect the reaction to be endothermic that is, one that absorbs energy from the surrounding environment. The dissolved liquid reactants need extra energy to make the jump to the gaseous product, so it takes energy in the form of heat from its surroundings (in this case, water). This makes the water's temperature fall. In our example experiment, the temperature of the water fell two degrees after adding the Alka-Seltzer. This is consistent with the sort of mildly endothermic reaction we'd expect.
A: Grab a clean container and fill it with water. Insert a thermometer into the container. Add one Alka-Seltzer tablet to the container. Measure the temperature when the reaction finishes. Estimate the enthalpy of the reaction.

Article: A rotary grater consists of a handle connected to a circular grating compartment. A side crank is then rotated to grate the cheese. Raise the top handle of the grater, place a small block of cheese into the compartment, and lower the handle. Grip the handle normally with your other fingers. For example, if you need to make nacho dips or breakfast casseroles, use a rotary grater.
Question: What is a summary of what this article is about?
Slice your cheese using a rotary grater. Apply some pressure to the top of the handle with your thumb. Rotary graters are safer as your hands are not required to press against the plates.They are also very efficient and are best reserved for making large quantities of shredded cheese.

Article: The amount should only be about the size of a grain of rice. While you want the primer to cover your eyelid completely, too much primer can completely backfire. It can cause your makeup to pill, clump, appear chalky or shiny. Too little, and your eye makeup won't stay. This amount of primer should be enough for both eyes. It's always better to start with less product and build layers if you need to instead of starting with too much and trying to wipe it off. Remember: less is more when it comes to primer. It should take about 20 seconds for the primer to absorb and dry. You can then apply your eye makeup as you normally would. Your eyelid should feel like a flat canvas and your shadow should go on smoothly. If it appears cakey or clumpy, you used too much primer and should use a little less next application. Try using the primer on your eyebrows to keep brow powder in place, too.
Question: What is a summary of what this article is about?
Dab a small amount of primer on the back of your hand. Allow the primer to dry before completing your eye makeup.