Quizzes, tests, exercises and puzzles for English as a Second Language (ESL), English as a foreign language (EFL), Teaching EFL (TEFL), Test of EFL (TOEFL), English for speakers of other languages (ESOL), Teaching ESOL (TESOL), TOEIC.
Fact
It is energy-efficient to turn off a fluorescent light only if it will not be used again within an hour or more. This is because of the high voltage needed to turn it on, and the shortened life this high voltage causes. .. More >>