Currently 94%of Web users use either Internet Explorer or Firefox．but recently somenew (71) have been developed that are beginning to attract attention．The browser Opera isbecoming very (72) because of its speed，it is currently the world’S fastest browsec andbecause it is much smaller (73) existing browsers(it can almost fit on a single diskette)．It canalso (74) the last web page you visited，so the next time you surf,you can start where you leftoff．And like the big two，you can get it for free；the catch is that you have to watch blinkingads in one comeL orpay$40 forthe ad—free (75) ofOpera．

A．readers
B．machines
C．techniques
D．browsers

连续抛掷一枚质地均匀的硬币9次，落下后出现正面朝上的结果是8次，抛掷第10次时，落下后正面朝上的概率是（    ）。