<p class="ql-block">watch a video about environment.</p><p class="ql-block">Problem：</p><p class="ql-block">People pour waste water into rivers.</p><p class="ql-block">Rivers are polluted and fish dies.</p> <p class="ql-block">why does the earth cry？</p> <p class="ql-block">Talk about other pollution</p>