Tại sao tế bào mạch gỗ được cấu tạo từ tế bào chết, còn mạch rây được cấu tạo từ các tế bào sống

Of the pollutants that form acids in the atmosphere, which is easiest to reduce? a. sulfur dioxide b. nitrogen dioxide c. ozone d. carbon monoxide

Which of the following is one of the four conditions necessary for natural selection to occur in a population? fewer organisms are born than the habitat can support mutation does not occur organisms have identical characteristics variation is inherited

15 ! come and answer! a(n) is the general term for an infectious disease that has spread across a city, region, or country.