Melina Kunar of the University of Warwick, and Todd Horowitz of Harvard Medical School ran a seriets of experimenis in which two groups of volunteers had to pay attention and retipond to a series of moving tasks on a computer screen that were reckoned equivalent in difficulty to driving.

华威大学的梅利娜·库娜和哈佛医学院的托德·霍罗威茨做了一系列试验，他们让两组志愿者注意电脑屏幕上的一系列移动任务并作出反应，这些任务被认为与开车的难度相当。

六级词汇讲解：

本句的主干是Melina Kunar…and Todd Horowitz…ran…experiments…。其中，in which two groups ofvolunteers…to driving属于“介词+关系代词”引导的定语从句，修饰先行词experiments，该从句中又包含一个that引导的定语从句，修饰先行词moving tasks.

reckon意为“认为”，此外它还含有“考虑;估计”之意。如：

I have to reckon the cost before I book the tickets.

我得先算一下费用，然后再订票。

equivalent意为“相等的;相当的”。如：

This qualification is equivalent to a degree.

这个资格证书相当于学位证。

六级考点归纳：

由“介词+关系代词”引出的定语从句须注意以下几个问题：米关系代词which和whom在定语从句中作介词的宾语时，介词可放在关系代词之前，也可放在该定语从句中的动词之后(此时，which可用that代替，whom可用who或that代替。在口语和非正式文体中，关系代词可以省略)。如：

I’m looking for afriend with whom I can chat on msn.

我在寻找一个能和我用msn聊天的朋友。

此句可以改为：I’m looking for afriend (who/whom/that) I can chat on msn with.

关系代词that在定语从句中作介词的宾语时，介词只能放在从句中de相关动词之后，不可放在that前面，但that可省略。如：

The position (that) she applied for is very attractive.

她申请的那个职位很有吸引力。(√)

The position for that she applied is very attractive.(x)在由“代词+ of+关系代词”结构引导的定语从句中，先行词指“人”时用whom，指“物”时用whicho如：

There are 50 students in my class, most ofwhom are girls.

我们班上有50个学生，其中大多数是女孩。

He has a large coUection ofbooks, many ofwhich are written in English.

他藏书很多，大部分是英文书。