分析错误:语法错误，意外'<'；第51-行

此处为new，并且有一个问题。我试图在代码中找到一个解析错误。消息中写着"第51行"，但我尝试过删除、标记，但没有解决。有人能为我指明正确的方向吗？因为我真的是php 的新手

<?php
/**
 * Variable product add to cart
 *
 * @author      WooThemes
 * @package     WooCommerce/Templates
 * @version 2.4.0
 */
if ( ! defined( 'ABSPATH' ) ) {
    exit;
 }
 global $product;
 $attribute_keys = array_keys( $attributes );
 do_action( 'woocommerce_before_add_to_cart_form' ); ?>
<form class="variations_form cart" method="post"      enctype='multipart/form-data' data-product_id="<?php echo absint(   $product->id ); ?>" data-product_variations="<?php echo esc_attr( json_encode( $available_variations ) ) ?>">
    <?php do_action( 'woocommerce_before_variations_form' ); ?>
    <?php if ( empty( $available_variations ) && false !==   $available_variations ) : ?>
        <p class="stock out-of-stock"><?php _e( 'This product is  currently out of stock and unavailable.', 'woocommerce' ); ?></p>
  <?php else : ?>
    <table class="variations" cellspacing="0">
        <tbody>
                <?php foreach ( $attributes as $attribute_name => $options ) : ?>
                    <tr>
                        <td class="label"><label for="<?php echo    sanitize_title( $attribute_name ); ?>"><?php echo wc_attribute_label( $attribute_name ); ?></label></td>
                        <td class="value">
                            <?php
                            $selected = isset( $_REQUEST[ 'attribute_' . sanitize_title( $attribute_name ) ] ) ? wc_clean( $_REQUEST[ 'attribute_' . sanitize_title( $attribute_name ) ] ) : $product->get_variation_default_attribute( $attribute_name );
                            wc_dropdown_variation_attribute_options( array( 'options' => $options, 'attribute' => $attribute_name, 'product' => $product, 'selected' => $selected, 'class' => 'sc-combobox' ) );
                            echo end( $attribute_keys ) === $attribute_name ? '<a class="reset_variations" href="#">' . __( 'Clear selection', 'woocommerce' ) . '</a>' : '';
                        ?>
                        </td>
                    </tr>
                <?php endforeach;?>
        </tbody>
    </table>
    <?php do_action( 'woocommerce_before_add_to_cart_button' ); ?>
    <div class="single_variation_wrap" style="display:none;">
        <?php
            /**
             * woocommerce_before_single_variation Hook
             */
            do_action( 'woocommerce_before_single_variation' );
          <div class="single_variation clearfix"></div>     <<--THIS IS LINE 51
        <div class="variations_button">
            <?php woocommerce_quantity_input( array( 'input_value' => isset( $_POST['quantity'] ) ? wc_stock_amount( $_POST['quantity'] ) : 1 ) ); ?>
            <button type="submit" class="sc-button single_add_to_cart_button button alt"><?php echo esc_html( $product->single_add_to_cart_text() ); ?></button>
            <input type="hidden" name="add-to-cart" value="<?php echo absint( $product->id ); ?>" />
            <input type="hidden" name="product_id" value="<?php echo absint( $product->id ); ?>" />
            <input type="hidden" name="variation_id" class="variation_id" value="" />
        </div>
            /**
             * woocommerce_after_single_variation Hook
             */
            do_action( 'woocommerce_after_single_variation' );
        ?>
    </div>
    <?php do_action( 'woocommerce_after_add_to_cart_button' ); ?>
<?php else : ?>
    <p class="stock out-of-stock"><?php _e( 'This product is currently out of stock and unavailable.', 'scalia' ); ?></p>
<?php endif; ?>
<?php do_action( 'woocommerce_after_variations_form' ); ?>
</form>
    <?php do_action( 'woocommerce_after_add_to_cart_form' ); ?>