How to Solve the Toefl test Question : - Incomplete Sentences

Question Example:

01. Violence on American campuses has abated ______ .
A. after 1970
B. in 1970
C. for 1970
D. since 1970

The answer of question is D ( Since 1970). The explanation is as follows:

In answering the incomplete sentence question, we must be able to identify the clue. In question 01, the clue is the verb has abated . This verb is used in present perfect tense. This tense requires the adverb of time using for and since. For is used with a duration of time such as three weeks, two years, five days, two hours, while since is used with a particular time such as yesterday, three weeks ago, I was a child, 1970, last week.


since + a particular time
Examples: since yesterday, since two weeks ago, since 1980, since last week, since I was a child.

for + a duration of time
Examples: for two weeks, for three days, for three years, for one month

Look at the examples of sentences below:

01. I have known him since I was a child.

02. She has lived her for two years.

03. They have come since yesterday.