空格前后出现by，两种情况要分开

黄晓丽

语法填空的设空形式分为有提示词和无提示词两种。其中，有提示词的空，括号中给出动词，要求考生填该动词的正确形式是必考点。需要注意的是，从高考题和模拟题来看，空格前后出现介词by的频率非常高。本文按by出现在空格前和空格后两种情况，分别阐述。

一、介词by位于设空提示词前

介词by位于提示词前这类考点比较简单，由于by是介词，后常接动名词或名词作宾语。因此，一般情况下，只需把括号里的动词转换为动名词（doing）或名词形式即可。

[例1]（2019年全国I卷）Scientists have responded by__________（note）that hungry bears may be congregating（聚集）around human settlements， leading to the illusion（错觉）that populations are higher than they actually are.

解析：由空前介词by可知，此处应填note的动名词形式noting。

[例2]（2017年全国I卷）Fast food is full of fat and salt; by__________（eat）more fast food people will get more salt and fat than they need in their diet.

解析：由空前介词by提示可知，此处应填eat的动名词形式eating。

二、介词by位于设空提示词后

介词by位于提示词后这类考点的考查比较频繁，难度较大。要求考生具有分析句子结构的能力，首先应该准确判断该空应填谓语动词还是非谓语形式。若应填谓语，则需根据句子的语境，准确判断动词的时态及语态;若应填非谓语形式，则根据句意，应填动词的过去分词形式，在句中常作定语和状语。

1. 考查谓语动词

根据句子结构，英语句子可分为简单句、并列句和复合句。

简单句只含有一个主谓结构。

并列句是由并列连词（and，or，but等）连接的两个或两个以上的分句，即：S1+并列连词+S2。

复合句是由“主句+引导词+从句（定语从句、状语从句、名词性从句）”构成的句子。

[例3] In fact， Chinese food in Boston __________（influence）by not just Chinese immigration to the city， but also the large Italian and Irish immigrant population there.

解析：因句中没有别的谓语动词，所以influence应为谓语动词;根据句意和by的提示可知，应填一般现在时的被动语态，即is influenced。

[例4]When the fish__________（find）by a fisherman in the Yangtze River Basin， it had been suffering from multiple injuries.

解析：因从句中没有别的谓语动词，所以find应为谓语;由主句时态可知用一般过去时;又根据句意和by的提示，可知用被动语态;故填一般过去时的被动语态，即was found。

[例5]Emerson Weber， a fifth-grade student in Sioux Falls， __________（know）by family and friends for the thoughtful and frequent letters she send， each wrapped in an envelope decorated with her own design.

解析：句中she send是定語从句，主语中缺少谓语，故know应为谓语动词;根据句意和by的提示，可知填一般现在时的被动语态，即is known。

2. 考查非谓语动词

[例6]__________（design）by IBM， Project Debater（辩手）is a machine that uses Artificial Intelligence（AI）to form a spoken argument.

解析：空格前没有主语，显然是非谓语动词;因句子主语Project Debater与design是被动关系，填过去分词designed，注意句首应大写，即Designed。

[例7]According to a survey __________（conduct）by sohu.com， only about40% of the 3500 people surveyed like the idea of“naked marriage”.

解析：因According to...是介词短语，而非句子，可知conduct为非谓语动词;又由conduct a survey（进行调查），且有by的提示，可知填过去分词conducted作后置定语。

[例8]（2015年全国I卷）A study of travelers __________ （conduct）by the website Trip Advisor names Yangshuo as one of the top 10 destinations in the world.

解析：因句中已有谓语动词names，所以conduct应为非谓语动词;由句意和by的提示，可知填过去分词conducted作后置定语。

[例9]（2015年全国II卷）The adobe dwellings（土坯房）__________（build）by the Pueblo Indians of the American Southwest are admired by even the most modern of architects and engineers.

解析：因句中已有谓语动词are admired，所以build应为非谓语动词;根据句意和by的提示，可知填过去分词built作后置定语。

[例10]Nearly three working hours __________（estimate）by the World Bank is lost each day， at a cost of billions of dollars each year.

解析：因句中已有謂语is lost，所以estimate应为非谓语动词;根据句意和by的提示，可知填过去分词estimated作后置定语。

巩固练习

1. The Chinese traditional culture can__________ （test）by the time.

2. They__________ （train）by their masters who had great experience with caring for these animals.

3. When the two online celebrities __________（interview）by reporters on Friday， the two seemed to have already forgiven each other after three days.

4. She initially __________（encourage）by her nephew， who asked Gan to be the main character in his short videos featuring country life.

5. Li Ziqi has risen to fame over the past years by__________（make）videos about traditional Chinese foods and village life.

6. In 1969， Nelson developed the idea for Earth Day after __________（inspire）by the anti-Vietnam War“teach-ins”that were taking place on college campuses around the United States.

参考答案

1. be tested 2. were trained 3. were interviewed 4. was encouraged 5. making 6. being inspired

责任编辑 蒋小青