Questions

When modifiers are misplaced or put in the wrong place, things can get quite confusing. A modifier adds detail or limits or changes the meaning of another word or phrase. 

Here Option A) "Covered in fluffiness, the couple played with the kitten" is the ony sentence contains a misplaced modifier. In the sentence, it gives the meaning that the couple are fluffy not the kitten.

A big bed of rock salt with the top portion of the bed containing potash (though not the variety used as ferilizer) has been discovered in Thar Desert at a depth of 100 metres. A massive belt of lead and zinc has been found in the Agucha area, while gold bearing rocks have been discovered in the Tuensang district of Nagaland.

The one word substitute for Very pleasing to eat is  Palatable. It means of food or drink that is very tasty, appetizing or pleasant to eat or drink.

DNA is a very long chain polymer made up of thousands of repeating units called nucleotides.

Nucleotide Unit is composed of a phosphate group, a pentose sugar, and a nitrogenous base.

The sides of the DNA ladder are made up of alternating deoxyribose sugar -- phosphate group units.

Valentina Tereshkova is the first woman to have flown into space