Stretch and tie

牵缀───Stretch and tie

A little tougher approach is to tie yourself up to a stretch cord and swim to the other end.───一个比较有难度的练习方式是在腰上系上橡皮筋不停地游到尽头。

laces together, stretch them between two tree trunks, tie them around and hang the plastic over, like a tent.───鞋带连在一起，绕过两棵树系起来，把塑料布放在上面，像一个帐篷。