—We are supposed to visit him from time to time. Then he won't feel _______.
A:alone, alone
B:lonely, lonely
C:lonely, alone
D:alone, lonely
电动机通电时转子转动,电能转化成 ____能。交流电动机也是靠着通电导体在磁场中 ____来运转的。电动机具有 ____、 ____、 ____、 ____、 ____的优点,广泛的应用在日常生活和各种产业中。
回答下列问题: