According to Jim Jennings, a spokesperson for Allstate Insurance Company, says the number one cause of distracted-driving accidents is cell phones.

VOA: standard.2010.06.24

One of the interesting properties of cells that are in exponential growth is that the time to increase the cell number by a factor of 2 is always the same.

细胞有一个有趣的性质,那就是在指数增长阶段,细胞增长的速度,永远是以二为底数来增长的

耶鲁公开课 - 生物医学工程探索课程节选

This makes sense; the rate at which the cell population is growing, the derivative dX/dt, is proportional to the number of cells I have.

这个说的通,细胞数目的增长速度,就是导数dX/dt,和细胞数目呈比例关系

耶鲁公开课 - 生物医学工程探索课程节选

If X is the number of cells, then the rate of change of X, dX/dt, the rate of change of the cell population, how fast division is taking is proportional to the number of cells I have.

如果X是细胞数目,那么X的改变率就是dX/dt,就是细胞数目的改变率,分裂的速度有多快,和细胞数量呈比例关系

耶鲁公开课 - 生物医学工程探索课程节选