采样时，无论是机械采样或人工采样，都应使采样器沿与煤流运行轨迹相垂直的方向截取一完整的煤流横截段为一子样。

It has been argued by some that gifted children should be grouped in special classes. The (31) has been on the belief that in regular classes these children are held back in their intellectual (智力的) growth by learning situation that has designed for the (32) children.

There can be little doubt that (33) classes can help the gifted children to graduate earlier and take their place in life sooner. However, to take these (34) out of the regular classes may create serious problems.

I observed a number of intelligent children who were taken out of a special class and placed in a regular class. In the special class, they showed little ability to use their own judgment, relying (35) on their teachers’ directions. In the regular class, having no worry about keeping up, they began to reflect voluntarily on many problems, some of which were not on the school program.

Many are concerned that gifted children become (36) and lose interest in learning. However, this (37) is more often from parents and teachers than from students, and some of these (38) simply conclude that special classes should be set up for those who are (39) . Some top students do feel bored in class, but why they (40) so goes far beyond the work they have in school. Studies have shown that to be bored is to be anxious. The gifted child whop is bored is an anxious child.

36（）

A.doubted 

B.bored 

C.worried 

D.tired