A:电流表坏了或未接好
B:从点a经过灯L1到点b的电路中有断路
C:灯L2的灯丝断了或灯座未接通
D:电流表和灯L1、L2都坏了
⒈重点短语:have to, look after, at home
⒉重点句式:①Thanks for… ②…can do sth. ③…be+v.-ing
Susan,
I'm sorry I can't……
Yours
Jane