A Family Heirloom
I live with my father in the summer, when I’m on vacation from school. Last week, he told me he had to go on a business trip in connection with his work (16)and that I’d be staying with his sister for three days. Although I love my aunt, I wasn’t happy about the prospect of three days at her house with nothing to do. It turns out I was in for a surprise.
Soon (17)after I arrived, my aunt said (18)she had a gift for me. “It belonged to my mother, your grandma. I’m sorry you never had the chance to know her,” she told me. I was expecting my aunt to hand me a ring or a bracelet, or maybe an old book, but instead she led me outside.(19)
 She pointed to a corner of the yard, where a tortoise was calmly munching a dandelion.  Rosie must have heard (20)us talking, because she began to amble over to us.  She was over a foot long and about seven inches high.  As soon as my (21)aunt assured me that Rosie wouldn’t snap or bite, I reached down to stroke her neck, admiring her brown and tan carapace, or upper shell.(22) Rosie, it turns out is: (23)a desert tortoise that my grandmother had started raising (24)over twenty years ago. My aunt said that she would have checked (25)with my parents, who each agreed that if I wanted to take responsibility for Rosie, I could take her home with me.It’s interesting that Rosie is older than I am. (26)Tortoises are land-dwelling, vegetarian turtles.
They can experience the satisfaction of contentment through (27)a diet of grass clippings, lettuce, broccoli, melons, and other vegetables and fruit. (28)They like to warm themselves in the sun but will burrow into the ground when they want to be safe and cool. I learned that I should build plywood enclosures in each of my parents’ backyards (29)so that Rosie would be safe year-round. I learned that tortoises are among the most endangered families in (30)reptiles. That means having a tortoise is a privilege, and I’m proud that my family has entrusted me with Rosie’s care. By caring for Rosie I’ll be able to share something with the grandma I never knew.
21. Which of the following alternatives to the underlined portion would NOT be acceptable?
A. After my
B. When my
D. Once my