Questions 18 to 20 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions. Now, listen to the passage.

What is one of the sources of the oceanic salinity

A．in spite of
B．regardless of
C．on account of
D．in case of

A．Accounting major.
B．Engineering major.
C．Science major.
D．Finance major.

A．The level of saltiness in the ocean is extraordinarily high.
B．The average level of salinity in the ocean is higher than that of inland lakes.
C．Salt has been gradually accumulating in the ocean, which leads to a rise in oceanic salinity level.
D．Salt has accumulated very quickly at the early stage of life formation, then this process gradually slow down.