Based on the context provided in the recruitment advertisement, the best answers for the numbered blanks are as follows:

**Question 13:**
Best answer: **A. in**
*Sentence: "Look no further! At Coffee Paradise, we offer a wide selection high-quality coffee beans from around the world."*

**Question 14:**
Best answer: **A. roast**
*Sentence: "Our beans are freshly ______ to ensure the best flavor in every cup!"*

**Question 15:**
Best answer: **B. Join**
*Sentence: "Enjoy a variety of blends, learn about the roasting process, and meet fellow coffee enthusiasts."*

**Question 16:**
Best answer: **C. percent**
*Sentence: "Plus, all attendees will receive a 20% ______ on their first purchase."*

So, the complete answers are:
13: A
14: A
15: B
16: C