题目

如图是小华配制100g溶质质量分数为5%的NaCl溶液的实验操作示意图：       （1）如图中的玻璃仪器分别是广口瓶、量筒、烧杯和玻璃棒，其中玻璃棒在此操作中的作用是 ______ ．   （2）指出图②中的一处错误操作 ____                    __ ．   （3）通过计算确定需要水的质量是 ______ g，配制时应选择 _____（填10、50或100）mL的量筒量取所需要的水．   （4）用上述图示的序号表示配制溶液的操作顺序 __          ___ The name of our galaxy, the Milky Way, comes from its appearance. It’s a milky white band of glowing light that spreads across the night sky. If you look up at the evening sky, there’s a good chance you will not be able to see what your grandmother saw when she was a little girl. A new study says that nearly 80 percent of people in North America can’t see the Milky Way because of light pollution.The most light-polluted country in the world is Singapore where researchers found that people living in the country never have the chance to experience true darkness. Other countries with large percentages of people living under such skies include Qatar, Kuwait and the United Arab Emirates.Too much light has a direct effect on human physiology and behavior. It can also destroy our sleep cycle. What’s more, it also affects wildlife. For example, baby turtles may not swim into the ocean because of street lights near shorelines.In the U.S., some communities have been taking action on light pollution but in developing countries, people still want to make bigger, brighter light, like LED lights. They can save energy, but on the other hand, they will increase light pollution rapidly in fact.There are still people that can remember when they used to be able to see the Milky Way, when they would walk outside at night, but those are becoming fewer and fewer.Nighttime natural scenery needs protection just like daytime scenery. Don’t let the Light pollution rob us of the chance to experience the wonder of a natural night sky.1.Why do we call galaxy the Milky Way?A.Because our galaxy looks like that.B.Because we look up at the evening sky.C.Because Grandma often tells us the story of it.D.Because many people in North America can't see it.2.Which of the following countries is the most light-polluted?A.Singapore. B.Qatar. C.Kuwait. D.The United Arab Emirates.3.The writer talks about baby turtles ___________.A.because the baby turtles are very lovely B.because they want to enjoy street lightsC.to show the bad effect of light pollution D.to help the animals to swim into the ocean4.We may see this article in .A.a travel guide B.a science magazine C.A news report D.a history project