If you don't spot an error in the sentence, immediately scan the answer choices for differences. Focus on one error at a time. Usually you will find a 3-2 or 2-2-1 split somewhere in the wording.
>> what does 3-2 or 2-2-1 split mean ?
This is the process of elimination usually done to eliminate the wrong answers. Check this question-
Rock samples taken from the remains of an asteroid about twice the size of the 6-mile-wide asteroid that eradicated the dinosaurs has been dated to be 3.47 billion years old and thus is
evidence of the earliest known asteroid impact on earth.
A. has been dated to be 3.47 billion years old and thus is
B. has been dated at 3.47 billion years old and thus
C. have been dated to be 3.47 billion years old and thus are
D. have been dated as being 3.47 years old and thus
E. have been dated at 3.47 billion years old and thus are
Okay, I went through the question and I couldn't spot the error! What do I do? I reduce my chances of picking the wrong answer and that I do by eliminating the wrong options. This elimination can be done by splits
Check the question. What is the subject? Rock Samples. Is it singular or plural? Plural! So the correct option should begin with have
How many options start with has
and how many do so with have
? 2 and 3 respectively. This is called 3-2 split because you have grouped the options on the basis of has
; there can be other conditions too for grouping options, as in two types of idiomatic usage in all the options listed and so on and so forth. Blindly eliminate the two options that start with the word has
and you have reduced the chances of your picking a wrong answer.
Hope that helps!
Is this okay?