Some students even have no idea of　　　they are studying, so they are aimless most of the time

On Sunday morning I helped my mother _______the cooking.

_ twice a year, whether itis a car or a bus or a truck, is the rule that every driver must obey in thiscity

Have you ever to Xi’an, Betty —Yes. I there last month.

Many difficulties ______ when Daisy helped endangered species of wildlife. [ ]