补字母uiu
问题描述：
补字母uiu
1.The network s___ has been improved.
2.The s___ on and around the Danube makes the river even more charming.
3.There are three g___ in the family,grandparents,parents and children.
4.Mother said to her son,"You are no longer a child ,you should learn to be i___."
答
1.The network service has been improved.
2.The signs on and around the Danube makes the river even more charming.
3.There are three grades in the family,grandparents,parents and children.
4.Mother said to her son,"You are no longer a child ,you should learn to be independent."