71.  Outer space exploring is the necessity of human being, s cognition, s development.

72.  What"s worse, if not well-ordered, dogs may attack people carelessly and cause accident.

73.  On the other hand, it"s inappropriate to carry dogs to some public places, when it may influence others.

74.  Although it is such s competitive society that money becomes much more vital than ever, romantic love is priceless.

75.  It; s out of question that the collage life ought to be colorful and full of happiness.

76.  It; s high time to look back on those days in the year of 2011 and look forward to the new year.

77.  On the contrast, if you forget "1", no matter how many "0"s behind, it equals nothing.

78.  However, people ' s opinions about this vary from person to person.

79.  They firmly point out that taking these subjects waste children"s too much time.

80.  What s waste of time!