生物体结构和功能的基本单位是（  ）

    Hello! I'm Chen Jie. I'm from China. I have four good friends. Mike and John are boys. Mike is from Canada. John is from the USA. Amy and Sarah are girls. They are from the UK. I like my friends.

我和mǔ  qīn____坐着小船，到乡下wài  zǔ  fù____家里去。天下着大雨，雨点打在船蓬上，shā  lā____地xiǎng____。船夫披着蓑衣在船后用力地摇着橹。

已知关于x的一元二次方程$\left(a-3\right)x^2-4x-1=0$，
（1）若方程有两个相等的实数根，求a的值及此时方程的根；
（2）若方程有两个不相等的实数根，求a的取值范围．

 What are you going to ____ (do) on sports day?