题目内容：

There is bad news for students who like to use their mobile phones while they study. New research shows that students do not learn very well when they text. Researchers    1.   （look）at 145 American high school students in the classroom. Some of the students used their mobile phones during class, while the others had their phones      2.      (switch) off. The head researcher, Dr Jeffrey Kuznekoff, said students   3.  did not use their mobile phones while the teacher was talking got    4.  (high) scores on tests they took at the end of the class.

One of the biggest    5.   (challenge) teachers have in the classroom is the non-stop battle of    6.   (keep) students working because students were more absorbed in social media than learning. Many students felt they needed to be online and check messages even they had important work to do in class.

   7.   is very common for students to be   8.  (physical) present in class, but mentally absent because they are using their mobiles. A study found that test scores increased 9. six percent after mobile phones    10.  (ban) in class.