<code id='4D1FB3F4D0'></code><style id='4D1FB3F4D0'></style>
    • <acronym id='4D1FB3F4D0'></acronym>
      <center id='4D1FB3F4D0'><center id='4D1FB3F4D0'><tfoot id='4D1FB3F4D0'></tfoot></center><abbr id='4D1FB3F4D0'><dir id='4D1FB3F4D0'><tfoot id='4D1FB3F4D0'></tfoot><noframes id='4D1FB3F4D0'>

    • <optgroup id='4D1FB3F4D0'><strike id='4D1FB3F4D0'><sup id='4D1FB3F4D0'></sup></strike><code id='4D1FB3F4D0'></code></optgroup>
        1. <b id='4D1FB3F4D0'><label id='4D1FB3F4D0'><select id='4D1FB3F4D0'><dt id='4D1FB3F4D0'><span id='4D1FB3F4D0'></span></dt></select></label></b><u id='4D1FB3F4D0'></u>
          <i id='4D1FB3F4D0'><strike id='4D1FB3F4D0'><tt id='4D1FB3F4D0'><pre id='4D1FB3F4D0'></pre></tt></strike></i>

          为什么歼-20用减速伞,而F-22不用,是技术落后吗?