1. Workers will have completed the new roads by the end of this year,
工人们将在今年年底把新路铺好。
知识点：介词by的多种用法：
用于被动语态：Thisstory was written by Shakespeare.
这部小说是莎士比亚写的。
在……边上：They told stories and sang songs by the campfire.
他们围在营火旁讲起了故事，唱起了歌。
以……方式：She earned money by writing.
她靠写作挣钱。
表示乘坐交通工具：They will be coming by train.
他们将会乘火车来。
“by + 时间”意为“到结束时” ：
by the end of this year 到今年年底
by the end of this term 到学期结束
by the end of spring / summer / fall / winter 到春末/夏终/秋尾/冬末
2. By the end of next year, they will have finished work on the new stadium.
到明年年底，他们将把新体育场建成。
知识点：此句为一个典型的“by the end of... +将来完成时”的结构。
