1. It is impossible -------- human beings to predict the earthquakes at present.

2. One of my co-workers came -------- with the flue on the first day of his business trip to New York.

3. Top motors corp. unveiled -------- new project, Self-Driving Car that will someday run through highways and roads of cities and towns

4. It is difficult to find -------- skilled and qualified candidates without investing much time and money.

5. Mr. McDonald -------- director of the company for ten years before he started a new business.