A：where
B：that
C：which
D：on which
ORDER FORM
Address: 12 Heping Street
Phone number: 628—2865
Order:
Dumplings: 12 beef and carrot dumplings
Soup: one tomato soup
Drinks: One large green tea and two small orange juices
函数y=1x+1-x2的定义域为（ ）
