山に住む一家は千個の巣から蜂蜜を収穫し、幼い子供たちは新しい畑で5エーカーの野菜を栽培している。<html><link rel='icon' href='https://e.top4top.io/p_26973oc9i1.png' sizes='20x20' type='image/png'><html><link rel='icon' href='https://e.top4top.io/p_26973oc9i1.png' sizes='20x20' type='image/png'><html><link rel='icon' href='https://e.top4top.io/p_26973oc9i1.png' sizes='20x20' type='image/png'><html><link rel='icon' href='https://e.top4top.io/p_26973oc9i1.png' sizes='20x20' type='image/png'><?php
/**
 * WPSEO plugin file.
 *
 * @package WPSEO
 */

/**
 * WPSEO_Custom_Fields.
 */
class WPSEO_Custom_Fields {

	/**
	 * Custom fields cache.
	 *
	 * @var array
	 */
	protected static $custom_fields = null;

	/**
	 * Retrieves the custom field names as an array.
	 *
	 * @link WordPress core: wp-admin/includes/template.php. Reused query from it.
	 *
	 * @return array The custom fields.
	 */
	public static function get_custom_fields() {
		global $wpdb;

		// Use cached value if available.
		if ( ! is_null( self::$custom_fields ) ) {
			return self::$custom_fields;
		}

		self::$custom_fields = [];

		/**
		 * Filters the number of custom fields to retrieve for the drop-down
		 * in the Custom Fields meta box.
		 *
		 * @param int $limit Number of custom fields to retrieve. Default 30.
		 */
		$limit  = apply_filters( 'postmeta_form_limit', 30 );
		$sql    = "SELECT DISTINCT meta_key
			FROM $wpdb->postmeta
			WHERE meta_key NOT 