Найдите в предложениях неличные формы глагола, подчеркните и назовите их:

a) Gerund; b) Present Participle Active;
с) Present Participle Passive; d) Past Participle Passive;
e) Perfect Participle Active;f) Perfect Participle Passive.

1. When keyed the data are held in a small memory called buffer.
2. Data keyed into the memory of a computer by typing on a keyboard are readable by humans.
3. Keyboard enables inputting numerical and text data.
4. The mouse provides the cursor control simplifying user's orientation on the display.
5. Having been constructed recently a new electronic device has important applications in space exploration.
6. Being supplied with a special appliance a television set may have a remote control.
7. The control unit operates by reading one instruction at a time.
8. Improved methods of obtaining three-dimensional television pictures have been worked on the basis of holography.

Не могу разобраться. Последнее задание осталось.