1. There is considerable debate over how we should react if we detact a signal from an alien civilization.

  2. The two world wars, whitch interruted the supply of raw material from Japan, also stifled the European silk industry.

  3. Migration is a complex issue, and biologists define it differently, depending in part on what sorts of animals the study.

  4. One way is by organizing backstage tours, so people can be shown round the building and learn how a theatre operates.

  5. What I'm afraid will happen is that books and magazines will all disappear, and there'll be just rows and rows of computers.

  6. The psychological laboratory has a strong claim to legitimacy and evokes trust and confidence in those who perform there.

  7. The displasys of art museums serve as a warning of what cirtical practices can emerge when spontaneous cirticism is suppressed.

  8. Vertical farming is an attempt to address the undoubted problems that we face in producing enought food for a growing population.

  9. It was not until 1500 BC, however, that the first hollow glass container was made by covering a sand core with a layer of molten galss.

  10. Many theorists believe the ideal boss should lead from behind, taking pride in collective accomplishment and giving credit where it is due.