泵站电缆的要求:橡套电缆无明显损伤,不露出芯线绝缘或屏蔽层,护套损伤伤痕深度不超过厚度(),长度不超过()(沿周长1/3),无()现象。
参考答案:1/2;20mm;老化
As we have planned, we’ll go to Beijing to attend her sister’s wedding party. We’ll also visit our mother school _______we go there.
A.unless
B.when
C.once
D.even if
人体平衡的特点?