there’s a factory method that creates derived classes of investment and the main advantage is that it supports a variable number of arguments! i’m still trying to decide if i like the flexibility or the speed better. you change from past tense to present tense after the first couple of sentences. in autumn 2, we had a very exciting science topic. 5. variable or changeable, as in feeling, purpose, or policy: versatile moods. to avoid a messy ‘add-on’ look, however, we would like to plan it all out in advance. 