根据图示要求，画出滑轮组的绕法。
（a）用最小的力将汽车拉动。 （ b）
略
考点：
分析：（1）首先要会组装滑轮组．知道承担物重的绳子段数越多越省力．在此题中，用最小的力将汽车拉动，所以要从动滑轮绕起．
（2）不计滑轮质量及转动摩擦，拉力是物体重力的几分之一，动滑轮就有几段绳子承担重力．
解答：解：（a）要使滑轮组最省力，需要承担物重的绳子段数最多，所以要从动滑轮绕起．
答案如下图：
（b）拉力F=G/3，动滑轮有3段绳子承担重力，应从动滑轮开始绕．
答案如下图：
点评：此题考查了滑轮组的组装．滑轮组的组装有两种方法，从定滑轮绕起或从动滑轮绕起．从动滑轮开始绕，承担物重的绳子段数多．
| Air France SA said Monday that its second-quarter net profit fell 35 percent to 57 million ($57.4 million), but sales were steady and operating profit surged. Earnings before interest and tax, a measure of operating income, gained 86 percent to 141 million as fuel costs fell and cargo traffic rose. Air France has been hurt less than rivals such as British Airways PLC and Lufthansa AG by the slowdown on North Atlantic routes following the war on Iraq in 2003 because it has fewer flights in that market. Net income fell as the airline paid deferred taxes that came due. Sales rose 0.9 percent to 3.2 billion. The carrier lost about 80 million in revenue because of a four-day strike by pilots in September. An accord was reached tying future pay increases to inflation. The carrier said that first-half fuel costs fell 15 percent to 680 million. Cargo traffic rose 11 percent in the second quarter, while passenger traffic rose 1.1 percent. The airline’ s shares gained 87 cents, or 7.7 percent, to close at 12.11. Separately, Air France and Alitalia SpA agreed to buy 2 percent stakes in each other as Europe’s second-and sixth-largest airlines deepen their partnership. |
" " in " 57 million" and " 141 million" probably stands for______.
A．English
B．the euro
C．European
D．European Currency Unit