If a table which has one Primary key and two alternate keys. How many Candidate keys will this table have ?

1. 1
2. 2
3. 3
4. 4

Write the missing statement to complete the following code:

file = open("example.txt", "r")
data = file.read(100)
............... #Move the file pointer to the beginning of the file
next_data = file.read(50)
file.close()

What will be the output of the following code ?

c = 10
def add():
    global c
    c = c + 2
    print(c, end = '#')
add()
c = 15
print(c, end = '%')

1. 12%15#
2. 15#12%
3. 12#15%
4. 12%15#

Which SQL command can change the degree of an existing relation ?