高中英语题
withacomputer____eachclassroom,thestudentscansurftheinternetconveniently.
a.havinginstalled
b.installed
c.equipped
d.equipping
whentheyfirstarrivedin____afamoustouristcity,itwasonlyasmalltown.
a.whatitisnow
b.whatisnow
c.whichnowis
d.nowis
答案分别为DB
为什么呢?其他选项为何不可呢?