В каком плане? cheap, cheaper, the cheapest? или что?
by next Tuesday указывает на то, что действие будет завершено к этому моменту в будущем = к следующему вторнику, и обычно данное выражение используется с Future Perfect.
Пример: I’ll have done all the work by next Tuesday.
1. My favorite activity is reading.
2. Her hobby is growing flowers.
3. Swimming is a good exercise.
4. Singing is my favorite work.
5. They stopped reading the notice.
6. He enjoyed listening to music.
7. I have finished cooking.
8. He misses teaching on Fridays.
9.I am good at playing football.
10.Reading helps you learn English.
Ответ должен быть вариант C