1.The biggest challenge in the d is a lack of water.
答案:desert
2.As we all know,there are two m political parties in the USA.
答案:major
3.During your journey,you should take care of your l .
答案:luggage
4.I asked for an e day to finish the work because it can’t be finished in a day.
答案:extra
5.When her son doesn’t get home on time,Mrs Wang always feels a .
答案:anxious
6.The sun appeared above the h (地平线).
答案:horizon
7.He noticed each bird had a unique f (脚印).
答案:footprint
