2.effective
柯林斯：Something that is effective works well and produces the results that were intended.
就是说如果你用effective修饰某物，你的意思是这个物体实现了它的预定目的。
Television is an effective means of communication.
电视是一种有效的通信手段。
《牛津词典》
总结：effective是做得到，efficient是做到并且做得快
三、拓展
1.efficiency/'f()nsi/n. 功效，效率
There is a big boost in employees' work efficiency.
员工的工作效率大大提高了。
2.inefficient/n'f()nt/adj.效率低的，能力差的，浪费的
The whole system is inefficient.
整个体系都效率低下。
《牛津词典》
