A、、 !DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"
B、、 !DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
C、、 !DOCTYPE html "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"
D、、 !DOCTYPE html