T (Thymus Derived) Lymphocyte Count. Definition. T cells are a type of white blood cells (lymphocytes). They make up part of the immune system. T cells help the body fight diseases or harmful substances. A test can be done to measure the number of T cells in your blood. Thymus derived lymphocyte count; T-lymphocyte count.
The road test generally takes 15 to 20 minutes. 1  If you fail the road test you must wait a minimum of two weeks (14 days) before taking the road test again and must pay another $40 testing fee. 2  Test results are valid for 2 years. If you fail the road test you must wait a minimum of two weeks (14 days) before taking the road test again and must pay another $40 testing fee. 2  Test results are valid for 2 years.
Upon successful completion of the eye test, you will take the examiner to your vehicle where they will ask you two questions related to car safety and car maintenance, known as the Show Me Tell Me questions. How long is the driving test explained in details. The introduction, the eye test and Show Me Tell Me questions will take around 10 minutes or so. A full description of this part of the driving test can be found in What to expect on the driving test.