单选题 If you feel you have a closer relationship with your grandmother on your mother"s side than on your father"s side, it is no surprise to researchers at the universities of Newcastle and Antwerp. 1 on studies in the Netherlands, they claim that maternal grandparents (外祖父母) are likely to make greater efforts to maintain frequent contact 2 their grandchildren than paternal grandparents (祖父母).
They 3 that psychological behaviors related to human evolution are involved: women are always sure of their relationship to their sons or daughters 4 men can never be wholly certain they are their children"s biological fathers.
Furthermore, maternal grandparents are always more certain than paternal grandparents 5 a grandchild is related to them: "Thus maternal grandparents may go the extra mile to visit their grandchildren."
The study, 6 by Thomas Pollet and his colleagues, found that for grandparents 7 within 30 km of their grandchildren, more than 30 per cent of maternal grandmothers and 25 per cent of maternal grandfathers had 8 daily or a few times a week. In 9 , this fell to 15 per cent for paternal grandparents.
Mr. Pollet said: "Even in families where there has been divorce, we found 10 differences. Grandparents on your mother"s side make the extra effort."

【正确答案】 A

【答案解析】[解析] 本题考查固定搭配。based on意为“以…为根据，基于…”；rely on意为“依靠，依赖”；agree on意为“就…达成一致”；take on意为“呈现”。根据句意，选A。

【正确答案】 B

【答案解析】[解析] 本题考查词义辨析。demand意为“要求，请求”；speculate意为“猜测，推测”；deny意为“拒绝，否认”；require意为“要求；命令”。根据上下文的意思可排除否定词义的C项；A和D均与文意不符，只有B项符合语境。

【正确答案】 D

【答案解析】[解析] 本题考查动词短语辨析。come across意为“过来，偶然发现”；cut back意为“减少，剪短”；cover up意为“掩盖，掩饰”；carry out意为“执行，开展(项目，研究等)”。根据横线前的名词study可判断这里是进行研究的意思，故D项正确。

【正确答案】 C

【答案解析】[解析] 本题考查动词的分词用法。living是分词短语做后置定语，修饰grandparents。live和其修饰语grandparents是主动关系，所以用现在分词形式，故选项C正确。depart意为“离开，出发”；exist意为“存在，(尤指在逆境中)生存”；emerge意为“出现，浮现”，均不符合句意。

【正确答案】 A

【答案解析】[解析] 本题考查语篇理解。由上文可知，外公外婆比爷爷奶奶更确定孙辈与他们的关系，因此他们会多走一些路去看望孙辈。因此下文所述研究发现住在30公里以内的祖辈中，超过30%的外婆和25%的外公与孙辈每天或每周联系几次。因此应选A。

【正确答案】 D

【答案解析】[解析] 本题考查介词短语辨析。in time意为“及时”；in detail意为“具体地”；in addition意为“另外”；in contrast意为“相比之下”。根据句意，此处要填入一个表示对比关系的短语，故选D。

【正确答案】 D

【答案解析】[解析] 本题考查形容词词义辨析。unchanging意为“不变的，恒定的”；unknown意为“未知的”；unlikely意为“不太可能的”；unexpected意为“意外的”。根据句中的“eyen”可知，研究的结果应该是意想不到的，故选D。