21. Detectives are investigating the company, three of _______ senior executives have already been arrested.

A. its               B. which            C. whose            D. those

22. Work over the past decade _______ that cracks produced by an earthquake can boost the shaking in future shocks.

A. revealed          B. has revealed         C. will reveal          D. had revealed

23. He asked Ginny if she would _______ to a small celebration after winning the scholarship.

A. consent           B. cease            C. compile          D. crush