根据首字母提示及句意，补全单词。

1. This is east, east points r ________.

2. I know they s ________ English and French in Canada.

3. Niagara Falls is a f ________ waterfall in Canada.

4. Beijing is the capital city of C ________.

5. — What c ________ is it?

    — It's red.

java中继承机制之所以能够降低程序的复杂性，提高编程的效率，主要是因为它使代码可 【8】 。