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.
1 You must pass the vision and road skills tests. 2  You must wait two-weeks to retest if you fail the skills test on the 1st or 2nd attempt to pass. 3  You must wait 60 days if you fail on the 3rd or subsequent attempt before being retested.ou must wait two weeks to re-test if you fail the skills test on the 1st or 2nd attempt to pass. You must wait 60 days if you fail on the 3rd or subsequent attempt before being re-tested. Driving Restrictions: 1  You may drive alone during daylight hours from 6 a.m. until 6 p.m. (or 8 p.m. during daylight savings time).