下列标点符号使用正确的一项是（    ）

先通读下面的短文，掌握其大意，然后根据短文内容和所给首字母，在空格内填入一个适当的词，使短文意思完整。所填单词在答卷横线上必须完整写出。
   I still remember visiting Moscow. It is the c ____ of Russia(俄罗斯), the b ____  country in the world. I go there with my parents at the age of eight. I live and study there for one year, I have some happy memories(记忆).
   One of the most interesting things of that city is that ，t____ are many dogs. Perhaps Russians l ____  dogs very much. You can see dogs here and there. Almost each of the families has a dog. I make friends with many Russian children w____  I am living and studying there. They are all very nice. They have fair hair and fair skin. I play with them h____  though（尽管）I can only speak a little Russian at first. They are f ____  to me. The weather in Moscow is very cold. It snows almost every day in w____ . The ground is always covered with a lot of snow. We often make snowmen t____ .
   Now I am b____   in China, but I miss them so much. I will never forget my happy memories of this visit to Moscow.

在探究“杠杆的平衡条件”实验中，所用的实验器材有：杠杆：（杠杆上每小格长为2cm）、支架、弹簧测力计、刻度尺、细线和质量相同的钩码若干个．