Each year, a large amount of medical waste is produced around the world. 【小题1】 But places like medical laboratories and medicine-making companies can also produce large amounts of medical waste.

Medical waste can be divided into several types. One important kind is the infectious (传染性的) medical waste. According to research, a large part of medical waste is infectious. Infectious medical waste includes different items. 【小题2】

Infectious medical waste can cause great harm to both people and the environment. 【小题3】 It must be properly managed and contained to avoid spreading infection. Other kinds of medical waste should also be managed and contained properly.

【小题5】 Part of the medical waste produced worldwide is burned. Some of the medical waste is buried underground. And some is directly poured into rivers, lakes and the ocean. All of the approaches are not environmentally friendly. Those in charge of medical waste management are working to develop greener methods of getting rid of medical waste.

Humans make mistakes. Even very experienced surgeons are not infallible. But what if these doctors could combine their knowledge with experience together and create a surgical standard of care, to be performed by machines?

That's the idea behind surgical robots, which may soon carry out most surgeries, from sewing up tiny wounds to performing heart procedures. Lots of these operations are actually already completed with the assistance of robots. However, a recent test suggests that robots in the operating room may soon go a step further, performing on soft tissue completely on their own, from the beginning to the end.

The Smart Tissue Autonomous Robot(STAR) has succeeded in completing surgeries on pigs. "We're the first to test out autonomous robotic surgery with soft-tissue surgery, and when compared to standard operation, it's better," says Peter Kim, a professor of surgery. "Our purpose is not to replace surgeons, but it will make the surgeons better and make the procedures safer."

A recent Mayo Clinic study discovered that most surgical errors-including operating on the wrong site or side of the body, or even leaving tools or objects inside the patient-occur every one out of 22,000 procedures. Though that's rare, robots like STAR would aim to lower the number even further.

In the surgical system called da Vinci, surgeons lay their arms inside instruments and use their hands to control the movement of robotic tools on the operating table from afar. Surgeons control the robot's every major move, and thus its results may vary based on the surgeon's training or experience.

On the other hand, STAR is entirely autonomous. Not only is it able to work on its own and perform surgeries with a more flexible "hand", but it's also able to react to the unexpected incidents. Cutting into hard tissue like bones is one thing, but operating on moving soft tissue is far more complex. STAR can respond to a changing environment, which is similar to how self-driving cars are programmed to not only drive on the high way, but also react to another driver who makes a mistake and gets in your way.

Patients and doctors alike have long believed in the healing（治疗）power of humor. It is claimed that humor not only affects patients' moods, but can actually help them recover faster.

Several studies seem to support this. Patients in better spirits are known to have a larger number of immune cells（免疫细胞）. Some have even claimed to have healed themselves of serious illnesses by reading comics and watching comedies.

Despite all this,many researchers are not convinced. They point out the fact that many sufferings have been known to disappear naturally, with or without a daily dose of laughter. They also say that while optimism in general does seem to be related to better health, it is hard to tell which comes first.

Humor in times of stress, however, clearly makes us feel better. On one level, it takes our minds off our troubles and relaxes us. On another, it releases powerful endorphins, a chemical produced by your body that reduces pain.

There are cases where the appreciation of a good joke is indeed directly related to a person's health. It can show, for example, whether a person has suffered damage to one particular area of the brain: the right frontal lobe（额叶）.

Scientists confirmed this by having people read jokes and asking them to choose the funniest endings from a list. Subjects with normal brains usually chose endings that were based on a relatively complex synthesis（综合）of ideas. Subjects with specifically located brain damage,however,responded only to slapstick（闹剧）endings,which did not depend on a particular context.When pressed,the brain-damaged subjects saw the logic in the correct endings.They simply did not find them funny.

Of course, humor is largely an individual matter. Next time your friend does not get one of your jokes, there is no need to accuse him of being a lame-brain（脑残）. However,you might suggest that he lighten up-for the health of it.