语法填空。
Opportunities don't come often. They come every once in a while. Very often, they come
quietly and go by without 1 (notice). Therefore, it is 2 (advise) that you should value and
treat them with care. 3 an opportunity comes, it brings a promise but never realizes it 4
its own. If you want to achieve something _ 5 intend to fulfill one of your ambitious, you must
work hard, make efforts and get prepared, 6 , you will take no advantage of opportunities
when they come to visit you. The difference between a man who succeeds and 7 who
does not lies only in the way each treats opportunities. The successful person always 8 (make)
adequate preparations to meet opportunity- ties as they duly arrive. The unsuccessful person, on
the other hand, works little and just waits to see them pass by. In my opinion, there are plenty of
opportunities for 9 in our society, but only those 10 are prepared adequately and qualified
highly can make use of them to achieve their purpose.
其中参数θ未知且
从总体X中抽取一个容量为8的简单随机样本，其8个样本值分别是1，0，1，-1，1，1，2，1。试求：
；