安全装置

Because they are adjusting to their new bodies and a whole host of new intellectual and emotional challenges, teenagers are especially selfconscious and need the confidence that comes from achieving success and knowing that their accomplishments are by others.

因为他们的自我意识强并且需要获得成功所必需的信心，所以青少年正在适应新的身体状况、心智和情感方面的诸多挑战，并且知道他们的成绩受到别人的。。。。。。

In color gradation. The color sensitivity of normal human vision is rarely

事实上，人眼对颜色梯度具有非凡的分辨能力。