我国已禁止在公共场所吸烟，因为香烟燃烧会产生有毒物质，影响吸烟者和被吸烟者的健康，被动吸“二手烟”是因为（　　）

若${\left(2x+\sqrt{3}\right)}^4=a_0+a_{1}x+a_2{x}^2+a_3{x}^3+a_4{x}^4$，则${\left(a_0+a_2+a_4\right)}^2-{\left(a_1+a_3\right)}^2$的值为（    ）

如果某人动脉出血，下列做法可取的是（　　）

    My grandpa has a farm. The farm is very big and beautiful. There are many animals on the farm. There are ten horses, seven goats, nine cows and many hens. The cows are black and white. The goats are white. The hens are very fat. My grandpa likes vegetables. So  there are a lot of potatoes, green beans, carrots and tomatoes. I like potatoes. My sister likes green beans. We all like this farm very much.