大家都搜：
这个实验很难
1、social experiment───社会实验
2、experiment───v.尝试；试验；进行实验；n.实验，试验；尝试
3、chromatography experiment───色谱实验
4、difficult tasks───艰巨的任务
5、more difficult───更难的（difficult的比较级）
6、quite difficult───非常困难
7、difficult times───困难时期
8、difficult───adj.困难的；不随和的；执拗的
9、is difficult───很难
1、No matter how difficult it is, he is determined to have a go at the experiment.───不论困难有多大，他都决心去尝试一下这个实验。
2、The inertial object with uncertain coefficient is a class of difficult object, in this paper, an method of control based on the experiment rule for the Si-Mo Furnace is developed.───变惯性系数惯性对象是一类较难控制的对象，例如文中所述硅钼炉的温度控制问题，作者采用经验规则控制方法解决了这类对象的有效控制问题。
3、Inverted pendulum system is difficult to control because of its instability. It becomes the wonderful experiment device to verify how about the control strategy in automatic control experiment.───倒立摆XiTong以其自身的不稳定性而难以控制，也因此成为自动控制实验中验证控制策略优劣的极好的实验装置。