Answer:
A. simple to construct and easy to repair
Explanation:
A dynamic microphone works on the principle of electromagnetic principle. A diaphragm is attached to a coil of wire which helps in producing sound. Responding to the sound waves, the coil of the wire is vibrated by the diaphragm. A magnetic field is created by the magnet which is present inside the coil of wire. The electrical signal is generated in response to the motion of the coil. The speed of the motion produces the amount of the current.
Since the construction of a dynamic microphone is easier as compared to any other microphone, John is likely to opt to build one.
1. Horsing around can lead to breaking equipment in the classroom or somebody getting hurt
2. leaving your backpack on the floor can cause someone to fall
3.something unexpected may happen and worsen the problem
4. it can corrupt the computer's files and deleted unsaved work.
if you want the sentences to be longer, add some words to them and make the message the same.
Answer:
1) Yes, Publisher relation should have a publisherID primary key.
2) NOT NULL and UNIQUE for the BookID, BranchID, CardNumber and name of the borrower in the Book, Book_Copies, Library_branch, and Borrower relations respectively. The DueDate field of the book_loan relation must be a time constraint. The BookID of the Book relation must be serial number for automatic addition and update of bookid across the database.
Explanation:
The Publisher relation should have primary key publisherID which should replace the publisherName in the Book relation to easily make a join query and attain a third-level database model.
