Лекция: Use the proper verb form.

1. Investigations were (to perform) at the temperature of 90 K in the external magnetic field. 2. Absorption spectrum (to have) been investigated in the 470–4000 cm–1 range. 3. Calculations (to indicate) that oscillations at frequencies as high as 3000 MHz may be possible. 4. An alternative approach is (to observe) the crystal surfaces. 5. The process involved heating (to follow) by cooling. 6. The advantage of silicon over germanium (to be) in lower cost. 7. Gold (to offer) the advantage of being chemically stable. 8. The limitation of the method is due to the fact that high temperatures are purely suited with the technology for (to fabricate) matrices.

3. Study the sentences given below. Change the parts of the sentences in the bold type by replacing infinitives by nouns or gerund in accordance with the following pattern:

The curveallows us to estimatethe energy barrier.

The curve allows estimatingthe energy barrier.

1. The equations enable the fundamental parameters to be determinedfrom experimental results. 2. The present investigation allows us to comparethe available data. 3. This made it possible to determinethe nature of the anomalous resonances in the spectral range 1000–3200 cm–1. 4. This permitted the experimenters to lower the condensation temperature. 5. The experimental data enabled the researchers to confirmthe advanced hypothesis.

(Based on Е.В. Владимирская и др., 2000).