15. The Sun, the Moon, the planets, and the stars all (rise) in the east and (set) in the west.
16. I often (learn) foreign languages very fast but I (experience) some problems with Chinese at present.
17. Her private doctor still (not - understand) much about the disease.
18. The number of cars in Vietnam (increase) significantly these days.
mn giúp em 4 câu này với ạ
