Several names exist for the magic circle, one of which is the Magic Loop. Fun fact: The Magic Ring is another name for it.
This was a bit of a trick question, though, because I've seen designers use two chains for the turning chain in a lot of patterns. In reality, though, two chains work best for a half double crochet, or half treble in the UK, and three chains work best for a double crochet stitch.
The "pencil hold," one of the two most common crochet hook holding techniques, is shown in the picture below.
For this question, Skein is the right response. Online articles about the various methods used to wind yarn abound; in fact, there are far more than just the three methods—skein, ball, and hank.
If you figured this one out, you must be an expert crocheter! I am by no means an expert crocheter, and I only recently learned this technique. A really clever method for joining two strands of yarn from two separate balls of yarn is the Magic Knot.
Yes, that image below depicts a Tunisian crochet hook! Although I haven't tried Tunisian crochet yet, I would really like to someday.
The shank, otherwise known as the shaft of a crochet hook is what determines the size of your hook. Essentially, a 3mm crochet hook has a 3mm shank/shaft.
