Десятичное число 25 в некоторой системе счисления записывается как 121. Найдите основание этой системы счисления.  А) 2      Б)3      В) 4       Г) 5

Complete the sentences .Use "heve to " in the correct tense.

1.He studied at a Canadian school.He ... learn English and Frensh.

2.Jessica writes about the wonders of nature.She ... trevel a lot.

3.Yesterday , her son fell ill and she ... stay at home .

4.My older brother wants to be musician .He play ... the violin for hours every day .

5.The students missed the bus and they ... walr to school im the rain.

6. If you want to learn more about Stinehenge , you ... read this book.

7.I can't play football this afternoon , i ... prepare for an exam.

Помогите пожалуйста!