5. Определите инфинитив в функции обстоятельства цели по месту относительно сказуемого

а) To change heat directly into electrical energy we must take two wires of dissimilar metals.

b) To change heat directly into electrical energy is not difficult.

c) To prove any statement it is necessary to make experiments and observations.

d) To prove any statement is a very difficult task.

e) To protect personnel from radiation is a very important task.

f) To protect personnel from radiation nuclear reactors are shielded with concrete walls.

6. Назовите предложения с инфинитивом в функции подлежащего

a) Тo prolong this discussion is to waste time.

b) To complete a journey round the sun requires nearly 30 years.

c) To complete this experiment he spent much time in the laboratory.

d) Tо lift a weight from the floor is to do work.

e) To give a true picture of the surrounding matter is the task of natural science.

7. Переведите предложения с инфинитивом в функции подлежащего (неопределенная форма глагола/отглагольное существительное)

a) То translate this text without a dictionary is difficult for him.

b) To obtain the number of watts is necessary.

c) To conduct an electric current is to transmit electrons.

d) To explore this region required two months.

e) To use atomic energy for peaceful purposes is the task of our scientists.

8. Переведите предложения с инфинитивом в функции обстоятельства цели (для, того, чтобы; для + сущ.)

a) Tо conduct an electric current we need a source of power.

b) The expedition left Moscow to explore that region.

c) To find out the quantity of energy in a body be spent little time.

d) To be ready for their exams the students had to study much.

e) I have to study better to pass all the exams well.

9. Переведите предложения, различая инфинитив в функции подлежащего или обстоятельства цели

a) To analyse this effect is to give special attention to all the elements of the circuit.

b) To analyse this effect we shall discuss all the elements of the circuit.

c) To heat a body heat must be applied to it.

d) To prove charging by induction is not difficult at all.

e) To prove charging by induction we have to make some experiments.

f) To prove charging by induction one has to make some experiments.

g) To solve the problem of pressure is absolutely necessary for our task..

h) To translate this text you should use a dictionary.

i) To melt this metal a higher temperature must be used.

j) To carry out this research work requires special knowledge and training.

k) We use thermometers to measure temperature.

l) We study English to read English books on our speciality.

10. Определите предложения с инфинитивом в функции именной части составного сказуемого (task + to be + Infinitive)

a) We were to maintain a flow of that liquid in the pipe.

b) Our duty is to defend our country.

c) That assistant was to compare the resistance of the two conductors.

d) We are to control the speed of these particles.

e) He is to demonstrate the results of his experiments next Monday.

f) His aim is to demonstrate the results of his experiment.

g) The only method to solve the problem is to make some experiments.