根据括号中所给的汉语写出单词。
⑴Those boys like playing hide-and-seek and often hide ____ (在…之中) the trees.
⑵How beautiful she is and her skin is as ____ (光滑的)as silk.
⑶She is looking forward to____ (收到) letters from her friends.
⑷The heavy smog makes it more difficult for us to see traffic signs ____ (清楚地).
⑸After several____ (星期) study, we will have our senior high school entrance exam.
B）根据句子意思，用括号中所给单词的正确形式填空。
⑹In the morning, taking a walk and____ (breathe) some fresh air are good for your health.
⑺He was ____ (terrible) hurt and had to stay in hospital for a long time.
⑻Many____ (wood) houses have been built for the tourists in this area recently.
⑼Mr. Brown ____ (prefer) hiking to running when he was in his twenties.
⑽Tian' anmen Square is always filled with ____ (visit) on National Day.

阅读《最后一课》选段，完成小题。

       忽然教堂的钟声敲了12下。祈祷的钟声也响了。窗外又传来普鲁士兵的号声——他们已经收操了。韩麦尔先生站起来，脸色惨白，我觉得他从来没有这么高大。

       “我的朋友们啊，”他说“我——我——”

       但是他哽住了，他说不下去了。

       他转身朝着黑板，拿起一支粉笔，使出全身的力量，写了两个大字：

       “法兰西万岁!”

       然后他呆在那儿，头靠着墙壁，话也不说，只向我们做了一个手势：“散学了，——你们走吧。

已知球O的直径为d，求球的表面积的一个算法分下列四步：

①计算S=4πR²；

②输入球的直径d的值；

③计算半径 $R=\frac{d}{2}$ ；

④输出表面积S的值，

其中正确的顺序是（   ）