其它
Eight pupils stand in a row to take a photo. Four of them insist on standing together. How many different ways are there to arrange them? 
Overseas Competition->Knowledge Point->Counting Modules
$8-4+1=5$  $5\times4\times3\times2\times1=120$  $4\times3\times2\times1=24$  $120\times24=2880$ 