Like you， plants need good things like food， water， and minerals in order to grow． Usually they get these important nutrients（营养） from the rich soil（土壤） in which they're planted． But there's another way to grow plants that doesn't use soil． It's called hydrogenic gardening．

    "Hydrogenic" means "working with water． " In a hydrogenic garden， plants grow with their roots in water， not in dirt． The water is filled with special food for the plants that gardeners have carefully measured and prepared．

    Hydrogenic plants grow quickly． In ordinary gardens， plants need time and energy to grow long roots that search the soil for food and water． In a hydrogenic garden， plants can use their energy to grow tall instead． And because there is no soil， there are no weeds and few insect pests（害虫）． Gardeners don't need to spray（喷洒） plants with dangerous chemicals． Both the plants and the environment stay healthy．

    Scientists hope that， one day， hydrogenic gardens may be able to help hungry people all over the world grow enough food﹣even in countries that have bad soil， or weather that is too hot， too cold， or too dry． And astronauts hope to take hydrogenic gardens with them to the spaceship they fly to Mars， so that they will always have fresh vegetables， and the fun of growing a garden without dirt．

（1）What's the meaning of the underlined word "dirt" in the second paragraph？　　

A． soil

B． water

C． insect

D． food

（2）Which of the following is NOT TRUE according to the passage？　　

A． Plants need water and other nutrients to grow．

B． There are no weeds inhydrogenic gardens．

C． Hydrogenic plants cannot grow in too hot weather．

D． Astronauts hope to take hydrogenic gardens to space．

（3）What's the passage about？　　

A． Plant growing．

B． Space farming．

C． Scientific watering．

D． hydrogenic gardening．