单项选择题

Some classes may also have a wide range of ages, so all classes are mixed ability, 1 the challenges are bigger in a large class. For example, 2 students may stop learning because they do not understand. The strong students sometimes dominate by gaining most of the teacher"s attention and by giving all the answers. Sometimes the stronger ones stop learning because they find the work too 3 and get bored. It is a big 4 to the teacher of a large class to help the weaker students and to keep the stronger students motivated so that all students succeed.
One way is to 5 move students around. You can do this by asking students to move around, 6 , to move forward one row each month. This means that they all get a regular chance of sitting in the front row, which gives students the best 7 of feeling involved and of receiving maximum attention and help from the teacher.
If you have a wide range of ages in your class, this may be less 8 because the older students may be taller than the younger students, and so the shorter students will need to be 9 the taller students. But whatever your classroom situation is, you can 10 a way of moving students so that different students have the chance of working with each other during the term.
Moving students around has other 11 too: it helps classroom discipline by preventing small groups, which may become disruptive, from forming. It also means that students of different abilities work together, 12 always having the stronger students in one row or group, and the weaker ones in another.
The teacher"s attitude towards a large class of 13 ability students can also have a good or bad effect on their attitudes to and successes in learning. If you use 14 words like "lazy" or "stupid" to students who may not 15 to be the fastest or best students in your class, you may have long-term problems with motivation and discipline.

(7)处填入()

A.evolution
B.chance
C.secret
D.level