依次填入下面一段文字横线处的语句，衔接最恰当的一组是(　　)
当年国语课本定位极为明确：________，________，________，________，________。
①吸收现代文明
②从而博纳多种价值和宽容各种思想
③继承传统价值
④不以强横的标准答案来桎梏学生
⑤以母语教育为本

Tom and Tim are brothers. They are Australians. They live in a mountain village(山村). Tom is 104 years old and Tim is 102 years old now. They1their story in a book called Enjoy Our Life.
Here is some of their advice for living a long, healthy life.
★Get up2. They get up at 6:30 or 7:00 in the morning.
★Have a3 breakfast. The brothers eat oatmeal (燕麦粥), half a banana, bread and eggs with a little cheese (奶酪).
★4 every day. The brothers like to climb mountains. They also walk on the hills (小山) every day.
★Eat a lot of 5, especially (尤其) garlic (大蒜). Garlic is good 6your health.
★Don’t eat a lot of salt (盐) and fat. These things are7 for your body (身体).
★8listen to the doctors always. Most of the doctors don’t know what to do with us. When something is9 with us, they don’t know how to treat (治疗) us. They are always surprised (吃惊) to see us to live so 10 .

下列各句中，划线的成语使用恰当的一句是（ ）

①f（f（x））=1；

②函数f（x）是偶函数；

③任意一个非零有理数T，f（x+T）=f（x）对任意x∈R恒成立；

④存在三个点A（x₁，f（x₁）），B（x₂，f（x₂）），C（x₃，f（x₃）），使得△ABC为等边三角形．

其中真命题的个数是（   ）