根据句意及首字母提示，写出单词。

1. There are many people in the supermarket. It's too c ____       

2. Traveling by train is the most c ____     way.

3. Lucy lives f_____ from school, so she has to go to school by bus.

4. It's the best way to g____ to school by bike.

5.M ___ than 50 teachers will come here tomorrow.

很多欧美人学了很长时间的汉语，写信时仍不习惯把日期写在信后右下角签名的下面，这种现象的存在是由于（）。