过去那里有一棵大树。
There _____________ be a big tree.
他年龄太小了，不能自己购物。
He is _______________ shopping by himself.
我认为现在还不是放松的时候。 我们仍然有许多要做的事情。
I _____. We still have a lot to do.
最近，科学家们正忙着撰写有关甲型H1N1流感的研究报告。
Scientists _____ the report on H1N1 Flu these days.
这位穷困的女孩非常幸运，她通过希望工程得到了许多书。
The poor girl was _____ she received many books from Project Hope.
吃含有苏丹红1号的食物是不安全的。
_____ to eat food with Sudan1.
