When l workde along the street,I was surprised to find that many people were wearing
问题描述：
When l workde along the street,I was surprised to find that many people were wearing
masks over their mouths for fear that________(他们可能会感染）H1N1(contract）
答
they should contract HINI.
用虚拟语气,表示对将来的假设——（当心）the glass.(look)Look out for the glass———再过半年（another）after another half year