分数单位是16的最简真分数有:16、56,
它们的和是:16+56=1;
故答案为:1.
A number of high buildings have arisen ______ there was nothing a year ago.
A.when
B.where
C.before
D.until
以下哪些疾病常见黄斑囊样水肿(如图) ()
A.缺血型视网膜静脉阻塞
B.葡萄膜炎
C.糖尿病性视网膜病变
D.白内障摘除术后
E.视网膜中央静脉阻塞