They (collect) ... more than 100 pounds of moon rocks and done science experiments on the lunar surface before they (come) ... back to the Earth.

On Feb. 15, 1971, Shepard and Mitchell (land) ... on the moon.

On this flight, Shepard (not orbit) ... the Earth.

They help women cope with emotional ... of divorce.

A. results  B. reasons  C. causes  D. consequences

Companies have to be ... to customer demand.

A. responsible  B. responsive  C. responding  D. responsively