Clinical trials are difficult - patients often wander off or drop out .
临床试验很难，患者经常会犹疑或退出试验。
The assumption is that one of the two will drop out in support of the other .
一种猜想是他们两人中有一个为了支持另外一个而退出。
Also some low-performing girls drop out of school making the tested sample unrepresentative of the whole population .
同样，一些低成绩的女孩退出了学校，使试验样本在整个人群中不典型.
Further showing gingrich 's advantage his lead over romney appears set to grow should other candidates drop out of the race .
进一步显示金里奇优势的是，如果其他参选人退出选举，他似乎还会进一步拉开与罗姆尼的差距。
Disillusioned those who cannot keep up just drop out .
令人心灰意懒的是，那些跟不上的学生只有退学一条出路。
But many aboriginal northerners drop out of school early and end up relying on government funds or public-sector jobs .
但是大部分土著的北方人早早的就退学了，最终靠政府基资助和公共部门的工作来生活。
One new initiative calls for local leaders to be dismissed whenever high numbers of girls drop out of school .
一项新的倡议提出，一旦有大量的女孩退学，当地的领导就应该被免职。
Those who drop out must compete with better educated people for jobs .
辍学者必须与受过良好教育的人竞争工作岗位。
Good teaching and research are not rewarded with extra funding or promotions ; institutions do not lose money if their students drop out .
优秀的教学与科研成果不会得到任何额外的奖励或升职；学院也不会因为学生的辍学而产生任何经济损失。
The son of an attorney and a schoolteacher gates entered harvard in the fall of 1973 only to drop out two years later to found microsoft with childhood friend paul allen .