题目

在下列各句空白处填入一个适当的单词，使句子意思完整、语法正确。【1】My friend learns English ________ watching videos.【2】To be ________, this is the worst movie I have ever seen.【3】Those two new cars ________ to my uncle. He bought them last month.【4】Sarah loves singing and playing the guitar. She is a _________ of American country music.【5】My brother hopes to study _________ and then come back to work at home.（在国内）玉米的果穗常有缺粒现象，向日葵子粒常有空瘪的，其原因主要是A．水分不足 B．传粉不足 C．光照不足 D．营养不足