Which protocol provides e-mail facility between different hosts?

Directions (55): Which of the following phrases given below each sentence should replace the phrase printed in bold letters to make the sentence meaningfully correct. Choose the best option among the five given alternatives that reflect the correct use of phrase in the context of the grammatically correct sentence. If the sentence is correct as it is, mark “No Error” as your answer.
 It is very critical that we don’t bury our heads in them sand and pretend that there is no job crisis but only some wage crisis, induced by labour market distortions.

In each of the following questions, sentences are given with blanks to be filled in with an appropriate word (s). Four alternatives are suggested for each question. Choose the correct alternative out of the four and indicate your choice for the correct answer.

Raja, two of________brothers attend primary school, wishes to be a school teacher after his graduation from the university.

India's First war memorial for animals will come up in which city?

What approximate value should come in place of the question mark (?) in the following question? 
21.9714 × (8.8749 - 4.9393) = ?

The area bounded by the lines x = 0, y = 0, x + y = 1, 2x + 3y = 6 (in square units) is