<header>
<h1>Reduce HTML</h1>
</header>
<body>
<script>
const currencies = ["", "USD", "EUR", "GBP", "UAH"];
let str = "<select>";
options = currencies.reduce((optionsStr, currency) => optionsStr += `<option>${currency}</option>`);
str += options;
str += "</select>";
document.write(str);
</script>
</body>