未分类题河道赛道场长120米,水流速度为2米/秒,甲船速度为6米/秒,乙船速度为4米/秒。比赛进行两次往返,甲、乙同时从起点出发,先顺水航行,问多少秒后甲、乙船第二次迎面相遇?D.54
未分类题“多行不义,必自毙”一句出自 ( )
不定项选择环戊酮与乙二醇在酸催化下反应得到缩酮化合物,因此可以认为缩酮化合物在酸性溶液中是可以稳定存在的。
未分类题It can be inferred from the passage that ______.A.the more we try to control our partners and relationships, the better we can enjoy loveB.the more frequently we fall in love, the more intelligent we'll beC.the more emotionally mature a couple are, the more harmonious they will liveD.it's unrealistic for you to search for true love from others
未分类题以下程序的输出结果是______。 int f() { static int i=0; int s=1; s+=i; i++; return s; } main() { int i, a=0; for(i=0; i<5; i++) a+=f(); printf('% d n' , a); }D.15