单选题According to this passage, ______ makes some kind of learning difficult.

单选题The speaker ________have criticized the paraprofessionals, knowing full well that they were seated in the audience.

单选题His emotional problems ______ from his experiences as a child, I think. A. stem B. flourish C. root D. sprout

单选题Only individual benefactors and {{U}}ad hoc{{/U}} grants have made possible the ecological surveys already undertaken.

单选题Phyllis Wheatley is regarded as America's first black poet. She was born in Senegal, Africa, about 1753 and brought to America aboard a slave ship at about the age of seven. John and Susannah Wheatley bought her for three pounds at a slave auction in Boston in 1761 to be a personal servant of Mrs. Wheatley. The family had three other slaves, and all were treated with respect. Phyllis was soon accepted as one of the family, which included being raised and educated with the Wheatley's twin 15-year-old children, Mary and Nathaniel. At that time, most females, even from better families, could not read and write, but Mary was probably one of the best educated young women in Boston. Mary wanted to become a teacher, and in fact, it was Mary who decided to take charge of Phyllis's education. Phyllis soon displayed her remarkable talents. At the age of twelve she was reading the Greek and Latin classics and passages from the Bible. And eventually, Mrs. Wheatley decided Phyllis should become a Christian. At the age of thirteen Phyllis wrote her first poem. She became a Boston sensation after she wrote a poem on the death of the evangelical preacher George Whitfield in 1770. It became common practice in Boston to have" Mrs. Wheatley's Phyllis" read poetry in polite society. Mary married in 1771, and Phyllis later moved to the country because of poor health, as a teacher and caretaker to a farmer's three children. Mary had tried to interest publishers in Phyllis's poems but once they heard she was a Negro they weren't interested. Then in 1773 Phyllis went with Nathaniel, who was now a businessman, to London. It was thought that a sea voyage might improve her health. Thirty-nine of her poems were published in London as Poems on Various Subjects, Religious and Moral. It was the first book published by a black American. In 1775 Phyllis wrote a poem extolling the accomplishments of George Washington and sent it to him. He responded by praising her talents and inviting her to visit his headquarters. After both of her benefactors died in 1777, and Mary died in 1778, Phyllis was freed as a slave. She married in 1778, moved away from Boston, and had three children. But after the unhappy marriage, she moved back to Boston, and died in poverty at the age of thirty.

单选题It will be emphasized that commercial space operations are inherently complex, long-term, capital-hungry, and Uset by/U a variety of risks.

单选题The traffic police stopped three trucks heavily loading with merchandise that looked as grain bags. A. that were loading... like B. loaded with... like C. to load with... for D. loaded with... for

单选题The couple consulted experts and decided to buy the new house on monthly payment plan.

单选题It was a small country house, but it was large ______ urban standards. A. at B. for C. by D. from

单选题 Some pioneering work that began as an attempt to discover ways to increase production efficiency led to the founding of the human relations movement in industry and to the development of motivational skills and tools for managers. In 1927 researchers were involved in determining the {{U}}optimum{{/U}} amount of lighting, temperature, and humidity (with lighting being considered the most important) for the assembly of electronic components at Western Electric. The researchers found that lighting had no consistent effect on production. In fact, production sometimes increased when lighting was reduced to the level of ordinary moonlight! The important part of this experiment began when two Harvard researchers, Elton Mayo and Fritz Roethlisberger, were brought in to investigate these unexpected results further. They found that workers were responding not to the level of lighting but to the fact that they were being observed by the experimenters. This phenomenon came to be known as the Hawthorne effect since the experiments were conducted at the Western Electric Hawthorne Plant. This was the first documented and widely published evidence of the psychological effects on doing work, and {{U}}it{{/U}} led to the first serious effort aimed at examining psychological and social factors in the workplace. Further experiments were continued for five years. Generally, the researchers concluded from their experiments that economic motivation (pay) was not the sole source of productivity and, in some cases, not even the most important source. Through interviews and test results, the researchers focused on the effects of work attitudes, supervision, and the peer group and other social forces, on productivity. Their findings laid the groundwork for modem motivation theory, and the study of human factors on the job, which continues to this day in such common practices as selection and training, establishing favorable work conditions, counseling, and personnel operations. The contributions of this experiment shifted the focus of human motivation from economics to a {{U}}multifaceted{{/U}} approach including psychological and social forces.

单选题The ultimate cause of the Civil War was the bombardment of Fort Sumter.

单选题Digitalis is a drug which is prepared from the seeds and leafs of a plant with the same name and is used as a cardiac stimulant.

单选题A notable lawyer in our city, the man is very busy.

单选题There are now______methods for studying color vision in infants than there once were.

单选题Machines that use hydraulic pressure including elevators, dentist chairs, and automobile brakes. A. exclude B. excluding C. include D. are included

单选题Nobody can help but be fascinated by the world into which he is taken by the science fiction.

单选题That not-well-planned proposal leaves______room for discussion. A．much B．a big C．a bigger D．a much bigger

单选题The insurance company paid him $5,000 in ______ after his accident.

单选题He is regarded by all as a genius,______the important discovery was made.

单选题"Disguise" in Paragraph 4 is closest in meaning to ______