题目

读量筒中液体体积时，某同学俯视读数为17mL则实际体积为（ ） A．等于17 mL    B．大于17 mL    C．小于17 mL    D．无法确定 答案：【考点】测量容器﹣量筒． 【专题】常见仪器及化学实验基本操作． 【分析】用量筒量取液体，应把量筒放在平整的桌面上，观察刻度时，视线、刻度线与量筒内液体的凹液面的最低处保持水平，再读出液体的体积数．否则，读数会偏高或偏低．例如，在俯视读数时，视线斜向下，视线与筒壁的交点Uncle Li and Uncle Wang are good friends. They live next to each other and their farms are both at the foot of the mountain. So they can help each other. But neither of them likes to use his head. They work hard but they are both poor. Most villagers have built new houses, but they still live in the low and broken houses. They never find out why.Once Uncle Li went to town to buy some medicine for his wife. In the town he heard the apples in a city were expensive. He told Uncle Wang about it as soon as he went back. They decided to carry some apples to the city. They borrowed some money from their friends and bought nearly 1,000 kilograms of apples in the villages and carried them to the city on a tractor(拖拉机). Bad luck! A lot of apples were in the city when they arrived. A few days later they had to sell them at a low price. They felt unhappy and returned to their village."I can't understand why we sustained (蒙受) losses(损失) in business while others always profit (盈利)" Uncle Li asked one day."The tractor was too small" Uncle Wang said without thinking. "We'll carry more apples on a truck next time!""I agree!" said Uncle Li. "How foolish we were!"1.Uncle Li and Uncle Wang live in the low and broken houses because ______.A. they hope to save moneyB. they're both poorC. their farms are at the foot of the mountainD. they're not far from their farms 2.The two farmers carried the apples to the city to _________.A. make a journey           B. visit some places of interestC. meet their friends       D. make a profit3.The two farmers had to sell their apples at a low price because ________.A. theirs weren't as good as the others' B. theirs were much less than the others'C. a lot of apples were in the cityD. they forgot to carry them on a truck4.Uncle Li and Uncle Wang were unhappy because _________.A. they had sustained losses in businessB. they had lost some money in the cityC. something was wrong with the tractorD. other people profited in the city5.Which of the following is true?A. The two farmers found out why they were poor.B. The two farmers will soon get rich.C. Neither of the farmers is clever.D. The two farmers decided to buy a truck.