ex1 :
1) will have
2) looked
3) had fed
4) would understand
5) would arrive
6) would have had
7) swim
8) press
9) had asked
10) would call
ex2:
1)will give
2)would not type
3)would have visited
4)attended
5)knew
6)had arrived
7)wouldn't make
8)were
9)find
10)would be
19đ/20đ
Nếu x+y+z=0 thì x=y=z=0
Nếu x+y+z khác 0
Ta có
\frac{x}{y+z+1}=\frac{y}{z+x+2}=\frac{z}{y+z-3}=\frac{x+y+z}{2(x+y+z)}=\frac{1}{2}=x+y+z
2x=x+z+1
2y=x+z+2
2z=x+y-3
Đến đây ta sẽ tìm được x y z