Cohort studies are generally preferred to casecontrol studies, since they involve far fewer statistical problems and generally produce more reliable answers.
队列研究一般优先用于病例对照研究，由于其很少涉及的统计学问题，产生的结果一般比较可靠。
2
In this case, the transition from manual to auto mated control would take place on the entrance ramp.
在这种情况下，从手动到自动匹配控制的过渡将在入口坡道上进行。
3
It is considered an important test case by both advocates and opponents of gun control.