Terms in a t-call block not showed as tranlatable in website builder in Odoo

I have a qweb t-call block ,there are some terms like "Special Price Offers", which aren't showed as translatable in website editor. Please check the qweb xml code below, and the screen shot. Can someone help? Thx

<template id="prduct_pricelist" inherit_id="website_sale.product" active="False" customize_show="True" name="Product Tiered Pricing">
        <xpath expr="//a[@id='add_to_cart']" position="after">
            <t t-call="product_tiered_pricing.web_pricelist"/>
        </xpath>
    </template>
    <template id="web_pricelist">
        <t t-set="pricelist" t-value="pricelist_items"/>
        <div class="product_pricelist">
            <t t-if="pricelist">
                <h4 class="mt-1">Special Price Offers</h4>
                <table class="table table-sm table-condensed text-center" id="pricelist_details">
                    <thead>
                        <tr>
                            <th width="100" class="text-center">Quantity</th>
                            <th width="100" class="text-center">Price</th>
                        </tr>
                    </thead>
                    <tbody>
                        <t t-foreach="pricelist" t-as="item">
                            <tr>
                                <td>
                                    <t t-esc="item['quantity']" class="text-center"/>
                                </td>
                                <td>
                                    <t t-esc="item['price']"/>
                                </td>
                            </tr>
                        </t>
                    </tbody>
                </table>
            </t>
        </div>
    </template>

Please see a screen shot in odoo website editor