расшифруй записи с столбиком аа+а2=баб

Задача на фотоефект. Помогите пожалуйста. Решается моя годовая оценка по физике:)

Електрон выходит с цезия с максимальной кинетической енергией 2 еВ. Какая частота света, которая излучает цезий,если работа выхода равняется

1.8 еВ.? 

X. Выберите один правильный вариант ответа. 1. …Tom and Bob good football players? A) are B) is C) was 2. My car isn't here any more. Somebody … it. A) stole B) have stolen C) has stolen D) had stolen 3. When I entered the room, she…on the sofa. A) lay B) is lying C) was lieing D) was lying 4. She never drinks strong coffee,…? A) ..., doesn't she? B) …, is she? C) …, does she? D) …, isn't she? 5. We are going for a walk. Who…to go with us? A) is wanting B) does want C) want D) wants 6. George…to a new flat a month ago. A) moved B) has moved C) had moved D) was moving 7. When we met our friends they…already…the news. A) knew B) have known C) had known D) has known 8. It…: the garden is covered with snow. A) is snowing B) snowed C) have been snowing D) has been snowing 9. This is the first time I…the caviar. A) ate B) had eaten C) am eating D) have eaten 10. I think Jane … a job. She has a lot of experience. A) will get B) will have got C) gets D) get 11. She …all the flowers by five o’ clock in the afternoon. A) watered B) has watered C) had watered D) will water 12. There…plenty of time to watch a football match on television yesterday. A) was B)were C)has been 13. The builders say that they…the roof by Tuesday. A) finish B) will finish C) will have finished D) have finished 14. He … a book all day yesterday. A) read B) was reading C) has read D) had been reading 15. When my brother…school he…to college. A) finish B) is finishes C) will finish D) finishes; A) will go B) goes C) is going D) go