By saying "As you experiment, avoid random motion", the author means you should ______ in order not to head in an opposite direction.

A．Because she wants to practice herself.
B．Bemuse she wants to work with the professor from Harvard.
C．Because she has to support the family.
D．Because she is tired of the classes.

A．It is a kind of costs the students should pay for studies.
B．It is a form of financial aid the students don’t have to pay hack.
C．It is the money that the students get from the colleges.
D．It is a kind of loans the students should repay when they have jobs.