Question

Carnivorous mammals can endure what would otherwise be lethal levels of body heat because they have a heat-exchange network which kept the brain from getting too hot.
A) which kept
B) that keeps
C) which has kept
D) that has been keeping
E) having kept

Answer 1

Hint: In the above question, we have to replace the underlined words ‘which kept’ with the correct words given in the options, such that the sentence is grammatically incorrect.
‘Which’ is used to convey additional information about something/ someone whereas ‘that’ is used to refer to something/ someone specific.

Complete answer:
Let us first understand the difference between ‘which’ and ‘that’.
The clause in a sentence that is used with ‘which’ can be omitted and still the meaning of the sentence will not get affected. For e.g. This box, which is black in colour, belongs to Adrija. Now, if we remove the clause with which, then also the meaning of the sentence is conveyed. ‘This box belongs to Adrija.’,also conveys the meaning.

The clause in a sentence that is used with ‘that’ cannot be omitted because the meaning of the sentence will get affected. For e.g. This box that is black in colour belongs to Adrija. The use of ‘that’ in the sentence implies a specific box and it is possible that there are more boxes other than this one. Therefore, if we remove the clause that is used with ‘that’, then the meaning of the sentence will change.

A) Incorrect answer - which kept is the wrong answer because the sentence is a ‘general truth’ related to carnivorous animals. These animals have not gone extinct and still exist therefore we cannot use past tense. Also, we cannot use ‘which’ because it will be grammatically incorrect.

B) Correct answer- ‘that keeps’, is the right answer because we use ‘simple present tense’ to tell a statement of ‘general truth’. ‘That’ is used because we a talking about a specific heat-exchange network

C) Incorrect answer- ‘which has kept’ is wrong because the sentence is a ‘general truth’ related to carnivorous animals. These animals have not gone extinct and still exist therefore we cannot use the present perfect tense. Also, we cannot use ‘which’ because it will be grammatically incorrect.

D) Incorrect answer- ‘that has been keeping’ ‘which has kept’ is wrong because the sentence is a ‘general truth’ related to carnivorous animals and we use ‘simple present tense’ to tell a statement of ‘general truth’.

E) Incorrect answer- ‘having kept’ is wrong because it will make the sentence grammatically incorrect.
The correct sentence will be :

Carnivorous mammals can endure what would otherwise be lethal levels of body heat because they have a heat-exchange network that keeps the brain from getting too hot.

Therefore the correct answer is option ‘B’.

Note: We generally use commas before and after the clause that includes ‘which’ in a sentence. For e.g. This box, which is black in colour, belongs to Adrija. However, we do not use commas in the sentence that contains a clause with ‘that’.