HTML 属性：size

<label for="firstName">First Name:</label>
<input id="firstName" name="firstName" type="text" size="10" />

<label for="lastName">Last Name:</label>
<input id="lastName" name="lastName" type="text" size="20" />

<label for="fruit">Favourite fruit:</label>
<select id="fruit" name="fruit" size="2">
  <option>Orange</option>
  <option>Banana</option>
  <option>Apple</option>
</select>

label {
  display: block;
  margin-top: 1rem;
}

<label for="fruit">选择一种水果</label>
<input type="text" size="15" id="fruit" />
<label for="vegetable">选择一种蔬菜</label>
<input type="text" id="vegetable" />

<select name="fruits" size="5">
  <option>香蕉</option>
  <option>樱桃</option>
  <option>草莓</option>
  <option>榴莲</option>
  <option>蓝莓</option>
</select>

<select name="vegetables" size="5">
  <option>胡萝卜</option>
  <option>黄瓜</option>
  <option>菜花</option>
  <option>芹菜</option>
  <option>油麦菜</option>
</select>