Find the missing character.

Select the letter-pair that can replace the question mark (?) in. the following series
BA, DC, FE, HG, ? , LK

In the following question, select the missing number from the given series.
49, 46, 43, 40, ?, 34

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.
COT, DQU, ESV, FUW, ?

Find the missing Number in the following questions :

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.
I, L, O, R, ?

In the following question, select the missing number from the given series.
19, 9, 28, 37, 65, ?

In the following question, select the number which can be placed at the sign of question mark (?) from the given alternatives. 

3, 7, 23, 95, ?