Pandas are famous animals. People like them a lot. The panda's face looks like a cat's, but its fat body and short tail(尾巴) are like a bear's. So people call this animal bear-cat. Scientists call it eat bear. The panda has a very mild temperament(性情温和). It is very loveable.

    The panda is an animal only living in China. The northeastern part of Sichuan Province and southern part of Gansu Province are its native home. Pandas like to climb trees. They live in the forests of high mountains eating bamboo and drinking spring water(泉水).

Sarah: Hi, friends! My parents will have a birthday party for me.

Amy: Great! When is your birthday?

Sarah: It's on May 12th. It's my eleventh birthday. Will you come?

Amy: Yes！What about you, John?

John: What day is your birthday?

Sarah: It's Saturday. We have no classes.

John: OK. I'll come. Do you like sports?

Sarah: Yes, I do. I like playing football very much.

John: Good! I'll give you a surprising gift.

    午后一点左右，从远处传来隆隆的响声，好像闷雷滚动。顿时人声鼎沸，有人告诉我们，潮来了！我们踮着脚往东望去，江面还是风平浪静，看不出有什么变化。过了一会儿，响声越来越大，只见东边水天相接的地方出现了一条白线，人们又沸腾起来。 那条白线很快地向我们移来，逐渐拉长，变粗，横贯江面。再近些，只见白浪翻滚，形成一堵两丈多高的水墙。浪潮越来越近，犹如千万匹白色战马齐头并进，浩浩荡荡地飞奔而来；那声音如同山崩地裂，好像大地都被震得颤动起来。

已知下列方程：①$x-2=\frac{2}{x}$；②0.3x=1；③$\frac{2}{x}=5x+1$；④x²﹣4x=3；⑤x=6；⑥x+2y=0．其中一元一次方程的个数是（　　）