Es ist auf jeden _____wichtig ,die Hinweise zu lessen .
参考答案： Fall
Water is a liquid which has no color _______ you wash your hands in it, then it turns black.[ ]
A. before
B. until
C. since
D. because
前往机场接团，地陪至少应提前（ ）分钟到达接站地点。
A．5
B．10
C．20
D．30
