Подчеркни правильную форму в предложении 'The hydrogen / Hydrogen is lighter than the atmosphere / atmosphere'.

Конечно, давай подчеркнём правильные варианты в предложениях: a) $\underline{\text{Hydrogen}}$ is lighter than $\underline{\text{the atmosphere}}$. b) $\underline{\text{The windows}}$ are made of $\underline{\text{glass}}$. c) Many people say they are interested in $\underline{\text{nature}}$ and the environment. d) We're studying $\underline{\text{grammar}}$ of $\underline{\text{English}}$. e) Most experts agree that $\underline{\text{the ice}}$ at the North and South Pole is melting. f) $\underline{\text{Gravity}}$ is the $\underline{\text{force}}$ of attraction between $\underline{\text{masses}}$. g) $\underline{\text{Global warming}}$ is causing a $\underline{\text{rise}}$ in temperature. h) $\underline{\text{The scientists}}$ have discovered a $\underline{\text{new galaxy}}$.