屋顶的两面斜面都有破瓦片.On both slopes of the roof there are broken tiles.伽利略让小金属球从斜面滚下.Galileo rolled small metal balls down the incline.图3.21画出了平行于斜面的、相互保持平衡的几个力.Figure 3.21 shows the forces parallel to the plane that are respons...
Brazil has felt vulnerable to soaring oil prices and to supply disruptions.巴西感到经受不了油价飞涨和供应中断的威胁.While these disruptions in life are not easy, they are necessary.即使这些碎片在生命里是很不容易的, 但却是必须的.Effects of machine failure , set -...
The roses are thorny. Take care not to prick your hands.玫瑰有刺,小心扎手.Prick the potatoes and rub the skins with salt.将马铃薯戳一些洞，并用盐揉搓外皮。The needle left a prick in the tailor's finger.裁缝的手指上有个针扎的孔。Prickle is a frequentativ...