It took them nearly 100 years to build the palace.(同义句) They

保证正确!
1.spent nearly,building
固定结构：spend some time doing sth 花费多少时间做某事
2.began
3.safety
4.Backpacking 背包旅行
5.did,start
如果对你有所帮助,请点击我回答下面的“选为满意回答”按钮,
再问： what can a police dog do?(回答) what can a rescue dog do?回答) what number should we dial when there is a fire?回答) what do you think a blind man needs our healthy people to do in his life?回答)
再答： 这个有难度，尽力而为吧： 1. A police dog can help find criminal clues and even the criminals. 2. A rescue dog can help judeg if there is anyone alive in the ruins. 3. 119. 4. Treating him equally to a normal man and giving some help if necessary.