[填空题]Since its (invent) ______, the telephone has become one of the most important telecommunication instruments in the world.

[填空题]Since its (invent) ______, the telephone has become one of the most important telecommunication instruments in the world.

[填空题]Since its (invent) _______, the telephone has become one of the most important telecommunication instruments in the world.

[填空题]How much has China reduced its population since 1970
China has already cut its rate of population growth by ______.

[单项选择]Since a circle has no beginning or end, the wedding ring is accepted as a symbol of ______ love.
A. successive
B. consecutive
C. eternal
D. insistent

[单项选择]Since 1975 there has been in the United States a dramatic decline in the incidence of traditional childhood diseases such as measles. This decline has been accompanied by an increased incidence of Peterson’s disease, a hitherto rare viral infection, among children. Few adults, however, have been affected by the disease.
Which of the following, if true, would best help to explain the increased incidence of Peterson’s disease among children ？（）
A. Hereditary factors determine in part the degree to which a person is susceptible to the virus that causes Peterson’s disease.
B. The decrease in traditional childhood diseases and the accompanying increase in Peterson’s disease have not been found in any other country.
C. Children who contract measles develop an immunity to the virus that causes Peterson’s disease.
D. Persons who did not contract measles in childhood might contract measles in adulthood, in which case the consequences of the disease would generally be more severe.
E. Those who have contracted Peterson’s disease are at increased risk of contracting chicken pox.

[单项选择]The question of where insights come from has become a hot topic in neuroscience, despite the fact that they are not easy to induce experimentally in a laboratory. Dr. Bhattacharya and Dr. Sheth have taken a creative approach. They have selected some brain-teasing but practical problems in the hope that these would get closer to mimicking real insight: To qualify, a puzzle had to be simple, not too widely known and without a methodical solution. The researchers then asked 18 young adults to try to solve these problems while their brainwaves were monitored using an electroencephalograph (EEG).
A typical brain-teaser went like this. There are three light switches on the ground-floor wall of a three-storey house. Two of the switches do nothing, but one of them controls a bulb on the second floor. When you begin, the bulb is off. You can only make one visit to the second floor. How do you work out which switch is the one that controls the light
This problem, or one equivalent to i
A. Theoretical brain-teasing problems,
B. Simple but rarely known problems.
C. Puzzling hut realistic problems.
D. Simple but theoretical problems.

[单项选择]

Since the energy crisis, these big cars have become a real liability. They cost too much to run（）

A. lack of reliability
B. substitute
C. costly means of transport
D. disadvantage

[单项选择]Since China has a large population, the popularization of private cars will only bring serious social problems（）
A. 自从中国人口变多以来，私家车的数量只是一个不太严重的社会问题。
B. 自从中国人口变多以来，私家车的流行会带来很多严重的社会问题。
C. 由于中国人口众多，私家车的数量只会带来社会问题。
D. 由于中国人口众多，所以私家车的普及只会带来严重的社会问题。

[填空题]Since 1979, China has adopted the significant policy of (11) to the outside world in the foreign economic relations and trade, actively developed the economic relations with countries (12) the world and made the unprecedented (空前的) achievements ever since the founding of the PRC. These have (13) very important roles in promoting international economic exchanges, speeding (14) the construction of China’s socialist modernization, strengthening the ability of self-reliance and contributing to the work of foreign affairs in the new (15) environment.