Questions

Any object rolls when there is no friction. So, Sliding to Rolling is correct.

A 40% solution of Formaldehyde known as Formalin is used in the preservation of biological specimens because of its hardening action on proteins. 

Free memory is maintained in linked lists, each of equal sized blocks. Any such block is of size 2^k. When some memory is required by a process, the block size of next higher order is chosen, and broken into two. Note that the two such pieces differ in address only in their kth bit. Such pieces are called buddies. When any used block is freed, the OS checks to see if its buddy is also free. If so, it is rejoined, and put into the original free-block linked-list.

In keeping with Prime Minister Narendra Modi's vision of a 'New India', Google India and the Ministry of Electronics and Information Technology (MEITY) announced a set of initiatives aimed at empowering citizens and creating abundant oppurtunities for all.

In all the given options, the countries are correctly matched with their National games.

USA - Baseball

Pakistan - Field Hockey

China - Table Tennis.

Gear finishing operation is called Burnishing.