2. 請簡述物件(Object)與類別(Class)的關係。

7. (10%) For the circuit in Fig. 7, \( V{\text{in}} \) and \( V{\text{out}} \) are input and output voltages, respectively, \( V{\text{b1}} \) is a dc bias voltage. (a) Is \( M1 \) a current course, common-source, common-drain, or common-gate amplifier? (b) Is \( M_2 \) a current source, common-source, common-drain, or common-gate amplifier? (You must explain.)