（全）剑桥英语语法在用 初级 Essential Grammar in Use 4th

Making your own vanilla extract is surprisingly simple. All you need is vanilla pods and alcohol. Split the pods, place them in a bottle of vodka, seal it, and leave it. Over a few months, the liquid transforms into a rich amber extract, pulling out the full depth of flavour from the beans. The longer you leave it, the better it gets. At the same time, you can create a simple syrup, gently boiling sugar and water until it thickens, ready to use in drinks or desserts. If you’re storing anything l