1.The fifth generation computers, with artificial intelligence,_____and perfected now.
a.developed
b.have developed
c.are being developed
d.will have been developed
2._______ the earth to be flat, many feared that columbus would fall off the edge of the earth.
a.Having believed
b.Believing
c.Believed
d.Being believed
3.If Icorrect someone, I will do it with as much good humor and self-restraint as if I were the one____.
a.to correct
b.correcting
c.having corrected
d.being corrected
1.The traditional approach_______with complex problems is to break them down into smaller,more easily managed problems.
a.to dealing
b.in dealing
c.dealing
d.to deal
2.The ancient Egyptians are supposed_______rockets to the moon.
a.to send
b.to be sending
c.to have sent
d.to have been sending
3.Until then , his family_______from him for six months.
a.didn’t hear
b.hasn’t been hearing
c.hasn’t heard
d.hadn’t heard