3.We could _______ the lights and fans when leaving the classrooms. (2.5 Điểm) turn on turn off turn down 4.In 2014, the ________ in Vietnam was over 93 million people. (2.5 Điểm) pollution overpopulation population 5."Thank you too much" (2.5 Điểm) you're welcome good idea no, problem 6.People use heat and light from the sun to make _______ (2.5 Điểm) solar power wind power nuclear power 7.There are lots of slums in big cities _____ there aren't enough houses (2.5 Điểm) so because of because 8.Good diets and healthcare usually create longer ______ (2.5 Điểm) healthcare life expectancy money 9.____ is a thick dark liquid under the ground that can be used to produce energy (2.5 Điểm) oil coal natural gas 10.Energy that can't be used again and again (2.5 Điểm) renewable non - renewable recycling 11.Maxwel ________ abroad next year (2.5 Điểm) is going to study plan to study will studies 12.Can you tell me _____ nuclear power? (2.5 Điểm) on at about