题目内容：

1.I don't buy that dress. Firstly，it was too expensive. _________，it was ugly.

2.Mr. Smith asked us not to talk in the room. _________，he talked loudly.

3.When our classmates have problems at school，we should ______ some help.

4.I know Alice's younger sister and I also know her _______ sister.

5.The sky was dark blue and _______ when the moon came up.