For each of the following sentences, choose the correct present perfect form of the verb.
For help with this exercise, see chapter 25 of Real Essays 5e.
Example
A number of recent crashes (to raise) questions about the risks of letting new pilots fly at night.
| A. |
| B. |
The National Transportation Safety Board (to investigate) the circumstances surrounding these fatal crashes.
| A. |
| B. |
The board (to state) that approximately eighty people die each year in crashes of privately flown planes.
| A. |
| B. |
Evidence (to show) that disorientation is a major risk for inexperienced pilots.
| A. |
| B. |
Nevertheless, the Federal Aviation Administration (to announce) that the current rules for new pilots are adequate.
| A. |
| B. |
Some experts (to argue) that these types of crashes have decreased in number over the last twenty years.
| A. |
| B. |
Other countries, such as Great Britain, (to create) laws that require new pilots to have special instruments for flying at night.
| A. |
| B. |
In many cases, these instruments (to help) disoriented pilots distinguish the earth from the sky.
| A. |
| B. |
As a result, the instruments (to prevent) pilots from crashing into the earth.
| A. |
| B. |
Many Americans (to write) to their representatives and senators to try to get similar legislation passed in the United States.
| A. |
| B. |