混频电路又叫混频器（MIX）是利用半导体器件的非线性特性，将两个或多个信号混合，取其差频或和频，得到所需要的频率信号。（）
参考答案：对
In relation to employment law:
(a) Explain the circumstances in which it may be appropriate for an employer to enter into a fixed term labour contract with an employee. (4 marks)
钻机变速箱的功用是（），并使回转器实现反转。
