The developing of the submarine was hindered by the lack of a power source that could propel an underwater vessel.

A motion picture provides us with both entertainment but also knowledge.

The company did not want to hire a man that his experiment was so limited.

The amount of women earning Master's Degrees has risen sharply in recent years.

The notion that students are not sufficiently involved in their education is one reason for the recently surge of support for undergraduate research.

Having finished his tem paper before the deadline, it was delivered to professor before the class.

For thousands of years, man has created sweet-smelling substances from wood, herbs and flowers and using them for perfumes or medicine.

What we know about certain diseases are still not sufficient to prevent them from spreading easily among the population.

Some of my friends are good at English while other are good at Mathematics.

This apprentice has spent two weeks to work on that new machine.

Those who had already purchased tickets were instructed to go to gate first immediately.

There are many different ways of comparing the culture of one nation with those of another.

Slowly and with care, the museum director removed the Ming vase from the shelf and placed it on the display pedestal.

Robots in the home might not be enough creative to do the cooking, plan the meal and so on.

A dangerously situation was created by the bad roads.

Although most species of small birds gather in groups at feeders provided by bird-watchers, the bright red cardinals usually appears alone or with its mate.

It is the recommendation of many psychologists that a learner ought to use mental images to associate word and remember them.

In most countries music songs are deeply personal and deal with themes of love, lonely, and separation.

By the time Robert will finish writing the first draft of his paper, most of the other students will have completed their final draft.

A smile can be observed, described, and reliably identify, it can also be elicited and manipulated under experimental conditions.

The Great Pyramid of Giza is said to have built over a 20-year period.