_________reached the classroom when the teacher came.
| A．We hardly had | B．Hardly had we |
| C．Hardly we had | D．Had we hardly |
Nothing is so easy as _____ parents to raise their expectations of their children too high.
| A．of | B．to | C．by | D．for |
The air quality in the city, ______ is shown in the report, has improved over the past two months.
| A．that | B．it | C．as | D．what |
Letterboxes are much more in the UK than in the US, where most people have a mailbox instead.
| A．common | B．normal | C．ordinary | D．usual |
When different cultures, we often pay attention only to the differences without noticing the many similarities.
| A．compared | B．being compared |
| C．comparing | D．having compared |
is our belief that improvements in health care will lead to a stronger, more prosperous economy.
| A．As | B．That | C．This | D．It |