题目内容：

As smart devices continue to fill people’s daily life, the debate over their place in the classroom has grown increasingly. Now, a study conducted at the United States Military Academy just might put an end to it.

In a recent investigation, researchers found that students who were permitted to use laptops or tablets in the classroom performed worse than those who did not- and those with higher initial GPAs（平均成绩）were most heavily affected.

While some argue that laptops aid students in notetaking and comprehension, many say that they couldn’t pay attention to the lessons. To get to the bottom of the issue, researchers investigated the effect of laptops and tablets on student performance in a course at a school.

In the study, the class was then divided into two “treatment groups”. The first treatment group was permitted to use laptops and tablets for purposes relating to their lesson. If the student was obviously distracted, professors could stop them from using the device. In the second group, students could only use tablets, making the screen easily visible to the professors. When it came time for final exam scores, the researchers found that using a laptop or tablet in the classroom had caused a drop of roughly one- fifth of a standard. The results for the two treatment groups were nearly the same, they say.

And, the negative effects were seen most heavily in male students. The estimated effects of the two treatment groups are nearly same, suggesting that even allowing students to use computer devices in a manner that is controlled by the professor can have harmful effects on classroom performance.

The researchers say that both unrestricted and restricted use may affect students in a number of ways. It could lead to distractions, in which students are checking social media or even doing homework for another class, and it may reduce students’ abilities to effectively take notes.

1.The underlined word “it” in the first paragraph may refer to        .

A. the device

B. the debate

C. the classroom

D. the study

2.Who suffered from the use of smart devices most in the study?

A. The male students with higher GPAs.

B. The students with poor academic performance.

C. The students who could use laptops or tablets freely.

D. The male students who could use laptops or tablets under control.

3.What caused the drop of the students’ scores?

A. The comprehension.

B. The note-taking

C. The distraction

D. The bad teaching