Chọn dấu thích hợp điền vào chỗ chấm: <span class="MathJax_Preview" style="color: inherit;"><span class="MJXp-math" id="MJXp-Span-1"><span class="MJXp-mstyle" id="MJXp-Span-2"><span class="MJXp-mn" id="MJXp-Span-3">300</span><span class="MJXp-mi MJXp-italic" id="MJXp-Span-4">c</span><span class="MJXp-msubsup" id="MJXp-Span-5"><span class="MJXp-mi MJXp-italic" id="MJXp-Span-6" style="margin-right: 0.05em;">m</span><span class="MJXp-mn MJXp-script" id="MJXp-Span-7" style="vertical-align: 0.5em;">3</span></span><span class="MJXp-mo" id="MJXp-Span-8" style="margin-left: 0em; margin-right: 0.222em;">.</span><span class="MJXp-mo" id="MJXp-Span-9" style="margin-left: 0em; margin-right: 0.222em;">.</span><span class="MJXp-mo" id="MJXp-Span-10" style="margin-left: 0em; margin-right: 0.222em;">.</span><span class="MJXp-mn" id="MJXp-Span-11">3</span><span class="MJXp-mi MJXp-italic" id="MJXp-Span-12">d</span><span class="MJXp-msubsup" id="MJXp-Span-13"><span class="MJXp-mi MJXp-italic" id="MJXp-Span-14" style="margin-right: 0.05em;">m</span><span class="MJXp-mn MJXp-script" id="MJXp-Span-15" style="vertical-align: 0.5em;">3</span></span></span></span></span><script type="math/tex" id="MathJax-Element-1">\Large 300cm^3 ... 3dm^3</script>