—The passage is too hard to understand.
—Yes, ________ it's very short and there are no few words in it.
A:so
B:as
C:because
D:though
某学生量取液体,仰视读数为30mL,将液体倒出一部分后,俯视读数为20mL,则该同学实际倒出的液体体积为( )