下列说法正确的是（ ）

根据短文理解，回答下列各题。

      CCTV reported that every year Chinese people throw away a lot of food; it can feed 200 million people for a year.

      Do we have too much food? Of course not. According to the UN World Food Program, there were 925 million hungry people around the world in 2010. Six million children die of hunger every year.

      Luckily, a number of people have realized the importance of saving food. Last November, Li Hong, a waitress in a restaurant in Nanjing, lost her job because she took some leftover(剩余的)food home for her son. Many people are by her side and criticized(批评)the waste behavior.

      What should we do in our daily life to waste less food? Here are some tips:

       ①Don't order too much food in a restaurant. Only order as much as you want to eat. If you cannot eat all the food you order, take the rest of it home.

       ②Don't be too picky(挑剔的)about food. Some food may not taste great, but your body needs it.

       ③Don't keep too much food at home, especially vegetables and fruit.

     “Every grain on the plate comes from hard work(谁知盘中餐, 粒粒皆辛苦).” It tells us everybody must save food.

若二次根式$\sqrt{x-3}$在实数范围内有意义，则x的取值范围是____.