If you()bright sunlight()dry wood with a g
问题:
If you()bright sunlight()dry wood with a glass, it will start burning.
A.expose;to
B.concentrate;on
C.aim;at
D.focus;on
If you()bright sunlight()dry wood with a glass, it will start burning.
A.expose;to
B.concentrate;on
C.aim;at
D.focus;on