echo count（strlen（“http:／／php.net”)); ？>的执行结果是？

A.echo $HOME

B.echo $USERDIR

C.echo $ENV

D.echo $ECHO

A.echo$10

B.echo${10}

C.echo$(10)

D.echo{$10}

A.echo $name+””

B.echo $name+$pass

C.echo $name.""+$pass

D.echo $name.$pass

A.echo $SHELL

B.echo $shell

C.ECHO $SHELL

D.echo SHELL

E.echo #SHELL

A.echo SHELL

B.echo $SHELL

C.echo $shell

D.echo shell

A.echo $SHELL

B.echo $shell

C.ECHO $SHELL

D.echo SHELL