Simplify the following text for a Grade 6 native English-speaking person.
Original: Crochet differs from knitting in that only one loop is active at one time ( the sole exception being Tunisian crochet ) , and that a single crochet hook is used instead of two knitting needles .
Simplified: It is similar to knitting , except that usually only one loop is active at one time , and that a crochet hook is used instead of knitting needles . Also , crochet can not be made by machine .