Tìm lỗi sai 21,That man is going to gets wet because he doesn't have an umbrella a.is b.gets c.because d.doesn't 22.Once when I was ten,I used to get sick and went to hospital a.was b.sick c.went d.to 23,Lan is not going to buy a big house yesterday a.is b.to c.big d.yesterday 24,Nam doesn't have to take his medicine yesterday because he was better a.doesn't have to b.his c.because d.better 25,We took all the rubish out side and burn it a.all b.outside c.burn d.it