Найдите герундий, в какой форме он используется:1)The teacher insists on carrying

Найдите герундий, в какой форме он используется:
1)The teacher insists on carrying out this experiment in our laboratory
2) Upon carrying out a number of expe-riments our students solved many interesting problems.
3) By using this law we define a unit change of electricity.
4) Heating the wire from 0 to 100 in-creases its resistance approximately by 40 %