单项选择题
A．at least thirty-five pounds B．exactly thirty-five pounds C．less than thirty pounds D．five pounds
A．they had to arm themselves with wooden sticks B．they protected themselves with stone clubs C．they had to travel in groups D．they never traveled at night
A．so we can travel anywhere without difficulty B．because we are provided with all kinds of convenient means for traveling C．because traveling organizations can be found in the countries the world over D．so travelers have increased rapidly