In the following passage some of the words have been left out. Read the passage carefully and choose the correct answer to each question out of the four alternatives and fill in the blank.

The Solar System has been a complicated wonder for the astronomers. This is a__(21)__to which we may never have the exact answer. Man has wondered__(22)__the age of the Earth__(23)__ ancient times. There were all kinds of__(24)____that seemed to have the___(25)___But man could not begin to think about the question scientifically until about 400 years ago when it was proved that the Earth revolved round the Sun and the Earth was a part of our Solar System, then scientists knew where to begin. 

Fill at the option (23).

18th World Wind Energy Conference and Exhibition (WWEC2019) was organized in which country?

Which is the fastest memory?

In which Prajamandal movement did the Kangar incident take place?

Directions: Few persons were seated in 3 different rows facing the north. The rows were numbered 1-3 such that the last row was numbered 1, the row exactly in front of it was numbered 2 and so on. The seats were numbered 1, 2, 3 and so on in ascending order from left to right. All rows did not necessarily have the same number of seats. The information about only few persons is known.
(i) S’s seat number was one less than as that his row number.
(ii) S was 2nd to the left of K. Nobody was seated to the right of N.
(iii) Row-1 had 6 seats.
(iv) T was seated at one of the extreme ends but not adjacent to R .
(v) Row 3 had one seats more than that in row 2.
(vi) M was 3rd to the left of P. M and P was not seated any extreme end of the row.
(vii) R was seated behind M, they had the same seat number but they were not in consecutive rows.
(viii) M not seated with N and T.
(ix) The maximum number of seats was six in any row.

How many persons could be there in the rows?

How was "24 December" celebrated in the country

Which state has recently launched online platform for issuance of certificates?

Necessary to get nuclear energy?