51.________.

28從毎小題的四個選擇項中選出最佳選項。

• A、friends

• B、passengers  

• C、neighbors

• D、customers

What will happen when students depend too much on research tools ?

• A、They won’t make good use of books.

• B、They don’t copy work done by others.

• C、Their studies will be greatly improved.

• D、Their attention to things will last longer.