油库自动付油控制系统误差主要由流量测量误差和()两大部分构成。
A.系统误差
B.允许误差
C.过冲量控制误差
D.基本误差
参考答案:C
How to protect children Web fans from unsuitable material on-line while encouraging them to use the Internet has long been discussed in the US. For some parents, the Internet can seem like a jungle, filled with danger for their children. But jungles contain wonders as well as dangers and with good guides, some education, and a few precautions, the wilds of the Internet can be safely navigated. "Kids have to be on-line. If we tell our kids they can’t have access to the Internet, we’re cutting them off from their future, " said an expert. Most kids have started to use search engines. Many of them are great for finding tons of interesting Internet sites, and they can also locate places where you might not want your kids to go. There are search engines designed just for kids. A certain software contains only sites that have been selected as safe. The most popular way to limit access would be to use what is known as a "content screener". But this can’t be wholly reliable, and the best thing parents can do is to talk to their kids and let them know what is OK or not OK to see or do on the Internet. Another way is that mum or dad is nearby when the child is surfing the Internet. A few other tips ·Don’t put the PC in a child’s room but keep it in an area where mum or dad can keep an eye on things. That also makes the Internet more of a family activity. ·Ask your child what he or she has been doing and about any friends they make on-line. ·Tell your child not to give on-line strangers personal information, especially like address and phone number. ·And tell your children never to talk to anyone they meet on-line over the phone, send them anything, accept anything from them or agree to meet with them unless you go along.
Which of the following is right according to the passage
A. Surfing the Internet is the best method of educating children.B. Children’s not having access to Internet may have effect on their progress.C. Using a content screener is most reliable for keeping children having access to Internet.D. Searching engines can help children to select materials fit for them.
初产妇,29岁,G2P0,现妊娠35周,既往孕24周因脊柱裂胎儿而行引产1次。此次妊娠早期经过顺利。妊娠32周时超声检查发现羊水过多,胎儿大于孕周,未见明显畸形。孕妇体态肥胖,近期有多饮、多食、多尿症状。
本例首先考虑的诊断是()
A.胎盘早期剥离
B.胎儿消化道发育异常
C.妊娠期糖尿病
D.母儿血型不合
E.风疹病毒感染