Based on the requirements listed in the job advertisement for a marketing staff position, here are the appropriate answers for the blanks in the questions provided:

**Ability (10)**: The correct option is likely **A. implement** (as one should be able to implement marketing plans).

**Ability (11)**: The best fit for this blank is **D. to** (the phrase would read "develop marketing plans and strategies").

**For Question 12**: The correct option is **B. with** (the phrase likely starts with "If you are ready, please send us...").

So, the answers would be:
- Question 10: A. implement
- Question 11: D. to
- Question 12: B. with