An alloy is a mixture of two or more metals, or one metal and something that isn't a metal. They are mixed together so well you cannot tell that the alloy is not a pure metal. Alloys typically have very different properties to the components that went into making the alloys. Alloys are often much, much stronger than their individual components. Many tools and machines are made from alloys because they need to be strong.
You annoy someone by bothering them until they are irritated, but not to the point of them being angry. The seagulls in the picture are annoying the people eating their lunch.
Corduroy is a type of fabric that has stripes on one side alternating between flat and slightly fluffy, which gives a ribbed effect. Corduroy is quite thick and is often used to make trousers and jackets.
You destroy something when you damage it so badly it is completely useless. You can destroy something by smashing it into tiny pieces, burning it or by dissolving it.
Illinois, abbreviated to IL, is a state in the north east of the United States of America. The capital of Illinois is Springfield. The largest city in Illinois is Chicago.