大规模开发和利用太阳能时，下列困难中，目前人们所关注解决的重点是（   ）

—It     be Tom's. In our class, only he is studying French.

    ①今天，这里有没有特务？你站出来！是好汉的站出来！②你出来讲！凭什么要杀死李先生？③杀死了人，又不敢承认，还要诬蔑人，说什么“桃色事件”，说什么共产党杀共产党，无耻啊无耻！④这是某集团的无耻，恰是李先生的光荣！⑤李先生在昆明被暗杀是李先生留给昆明的光荣！也是昆明人的光荣！

    去年“一二·一”昆明青年学生为了反对内战，遭受屠杀，那算是青年的一代献出了他们最宝贵的生命！现在李先生为了争取民主和平而遭受了反动派的暗杀，我们骄傲一点说，这算是像我这样大年纪的一代，我们的老战友，献出了最宝贵的生命！这两桩事发生在昆明，这算是昆明的光荣。

研究发现：人和猿在骨骼结构上几乎相同；人和猿的盲肠都有蚓突：人和猿在胚胎发育的前五个月完全一样．这些事实说明了（    ）

阅读短文，选择正确的答案。

    There are many apple trees in a garden. They're good friends. One day an old tree is ill. There are many pests in the tree. Leaves of the tree turn yellow. The old tree feels very sad and unwell. Other trees send for a doctor for him. At first, they send for a pigeon, but she has no idea about it. Then they send for an oriole(黄鹂), and she can't treat the old tree well either. Then they send for a woodpecker. She is a good doctor. She pecks a hole in the tree and eats lots of pests. At last the old tree becomes better and better. Leaves turn green and green.