—_____________ has Hong Kong been back to our motherland?

—For 20 years. How time flies!

生态系统的组成成分有哪些？

在等差数列$\left\{a_n\right\}$中，已知$a_1+a_2+a_3+a_4+a_5=20$，那么$a_3$=

    I'm Simon from America. I am twelve and I'm at Wllize junior School(初中). This month We have two school events(事件). One is an English party and one is a school trip. Next month, there will be five events.

    Here is a list.   

    I'm in the school volleyball club. 1 also like singing. 1 want to play in the volleyball game and sing at the music party. 1'm very happy.