等质量的水、氢气、硫酸中都含有相同的（ ） A．氢分子 B．氢原子个数 C．氢元

若关于x的方程式x²﹣x+a=0有实根，则a的值可以是

A．2

B．1

C．0.5

D．0.25

从细胞的结构看，“种瓜得瓜，种豆得豆”这种现象主要决定于     。

企业会计核算必须符合园家的统一规定，这是为了满足( )要求。

A．一贯性原则
B．重要性原则
C．可比性原则
D．配比原则

Reading Comprehension.

     Communications technologies are far from equal when it comes to conveying the truth. A recent

research shows people tend to tell more lies in phone conversations than they are in emails. The fact that

emails are automatically recorded and can come back to haunt you appears to be the key to the finding.

     Jeff Hancock of Cornell University in Ithaca, New York, asked 30 students to keep a communications

diary for a week. In it they noted the number of conversations or email exchanges they had lasting more

than 10 minutes, and confessed to how many lies they told. Hancock then worked out the number of lies

per conversation for each medium. He found that lies made up 14 percent of emails, 21 percent of instant

messages, 27 percent of face-to-face interactions and an astonishing 37 of phone calls.

     His results to be presented at the conference on human-computer interaction in Vienna, Austria, in April,

have surprised psychologists. Some expected emailers to be the biggest liars, reasoning that because deception

makes people uncomfortable, the detachment (非直接接触) of emailing would make it easier to lie. Others

expected people to be more in face-to-face exchanges because we are most practiced at that form of

communication.

     But Hancock says it is also crucial whether a conversation is being recorded and could be reread, and

whether it occurs in real time. "People appear to be afraid to lie when they know the communication could

later be used to hold them to account," he says. This is why fewer lies appear in email than on the phone.

     "People are also more likely to lie in real time in an instant message or phone call than if they have time to

think of a response," say Hancock. He found many lies are spontaneous responses to an unexpected demand,

such as, "Do you like my dress?"

     Hancock hopes his research will help companies work out the best ways for their employees to

communicate. For instance, the phone might be the best medium for sales where employees are encouraged

to stretch the truth. But, given his result, work assessment where honesty is a priority, might be best done

using email.

1. Hancock's study focuses on ______. [ ]

A. the consequences of lying in various communications media

B. the success of communications technologies in conveying ideas

C. people are less likely to lie in instant messages

D. people's honesty levels across a range of communications media

2. Hancock's research finding surprised those who believed that ______. [ ]

A. people are less likely to lie in instant messages

B. people are unlikely to lie in face-to-face interactions

C. people are most likely to lie in email communication

D. people are twice as likely to lie in phone conversations

3. According to the passage, why are people more likely to tell the truth through certain media of

    communication? [ ]

A. They are afraid of leaving behind traces of their lies.

B. They believe that honesty is the best policy.

C. They tend to be relaxed when using those media.

D. They are most practiced at those forms of communication.

4. It can be inferred from the passage that ______. [ ]

A. honesty should be encouraged in interpersonal communications

B. more employers will use emails to communicate with their employees

C. suitable media should be chosen for different communication purposes

D. email is now the dominant medium of communication within a company

试述顶注式，底注式和阶梯式浇注系统各有什么优缺点？