单选题 Counts could also be _____ by making scratches in the dirt or on a stone, by cutting notches in a piece of wood,or by tying knots in a string.无

【正确答案】 A

【答案解析】句意：计算也可以靠在泥土或石头上划痕、在木头上刻凹痕、或者在绳子上打结来进行。本题考查动词词义辨析。 maintain表示“保持，维持”，符合句意，故选A。justify证明……是正当的。assert断言；主张。locate定位。