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
1.a approach后接名词和动名词，approach to doing sth. 2.c be supposed to "应该，被期望"，表示对过去发生的事情的判断，用完成时. 3.d until then 是时态的标志，until要用完成时，then可以看出主句的行为发生在前，应该用过去完成时。