【小题1】I don't buy that dress. Firstly，it was too expensive. _________，it was ugly.
【小题2】Mr. Smith asked us not to talk in the room. _________，he talked loudly.
【小题3】When our classmates have problems at school，we should ______ some help.
【小题4】I know Alice's younger sister and I also know her _______ sister.
【小题5】The sky was dark blue and _______ when the moon came up.