Task 5. Choose Present Perfect or Present Perfect Continuous for each situation
e. g. Kate/ travel/ for 2 months- Kate has been travelling for 2 months She/ visit/ 5 countries- She has already visited 5 countries 1. a) My brother is an actor. (he/appear) in several films. b) (He/ act in films) since he was 10 years old 2. a) Liz is a writer. How long(she/write) books? b) How many books(she/write)
Life appeared on Earth about 3.5 billion years ago. Since then, the Earth's biosphere significantly altered the atmosphere and other abiotic factors, causing the quantitative growth of aerobic organisms as well as the formation of the ozone layer, which together with the Earth's magnetic field weakens harmful solar radiation, thereby maintaining the conditions for life on Earth