单项选择题 In winter drivers have trouble stopping their cars from （） on icy roads.

单项选择题As the director can't come to the reception, I'm representing the company（）.

A．on his account
B．on his behalf
C．for his part
D．in his interest

单项选择题Many people are （） to insect bites, and some even have to go to hospital.

A．insensitive
B．allergic
C．sensible
D．infected