Questions

Database provides necessary means to achieve this abstraction. By structure of a database we mean the data types, relations, and constraints that should hold on the data.

Laconic means using only few words in his/her speech or while talking.

In the given options, talkative, wordy and long are all opposite to laconic and brief is the only word which is similar in meaning of laconic.

Molecular compounds are those with covalent bonds between the elements and those elements are typically non metals.

Here in the given options, Ar is an element. NaI has an ionic bond. Hence, N2O4 has a covalent bond between the two non metals and is a molecular compound.

Fathometer is used to measure the depth of the ocean.