杠杆在生产、生活中有着广泛的应用，如图所示，下列工具中属于费力杠杆的是
A．①、②
B．②、③
C．①、③
D．①、④
答案：B
看图完成短文，每空一词
Look at the picture. I'm a 1 . My name is Panpan. I'm 2 China. I like eating 3 . I 4 in the
forest. My favourite activity is 5 trees. I have got a friend. It's a 6 . The monkey's name is Lingling.
She likes eating 7 . She comes from 8 , too. 9 is her favourite activity. We play 10 day. We
have a good time.
计算：
（1）2a2-a8÷a6
（2）（2-x）（2+x）-（x+4）（1-x）
