Choose the correct form of the Participle. 1. (to name) geometric ideas we usually use letters of the alphabet. 2. We insisted on the (to follow) notation of the geometric object. 3. (to divide) both the numerator and the denominator by х you will get the following expression. 4. When (to speak) with my science adviser I got better understanding of the latest development in my special field. 5. The properties of the material (to use) in the experiment now are given in the latest article. 6. The advantages of the new system (to prove) by many tests are very important. 7. Two angles (to have) the same vertex and a common side are refered to as adjacent angles. 8. The concepts (to introduce) at the seminar should be considered in detail. 9. The (to obtain) difference must be checked carefully. 10. The (to expect) result must prove that this law holds for similar cases.