单位重量或体积的燃料完全燃烧时所放出的热量称之为燃料的发热值。

如图各项基因组成的个体，自交后代表现型比为9：3：3：1的是[     ]

A．

B．

C．

D．

在海港工程中，采用涂层保护工艺的钢管桩，其涂层应伸入桩帽（或横梁）混凝土内（）。

A.0～50mm

B.50～100mm

C.100～150mm

D.150～200mm

阅读理解。

     Whether you're considering a first cell phone for your teen or trying to limit various functions on your

child's existing cell phone, it's important to understand the various controls and technologies available

today.

     The decision to get your child's first cell phone usually occurs when you're annoyed by your kid, who

insists that "everyone" has one. Whether that's accurate or not is probably of little interest to your child,

but it's typically his or her biggest selling point!

     Often parents recognize the safety features of the child's carrying a cell phone, including the ability to

communicate easily with parents by voice or text messaging. Convenience is also a large factor -knowing where in the mall to meet your child, or getting the notice that soccer practice has been delayed. It leads

to efficiency, convenience and safety for both you and your child.

     But what about the downsides (负面影响) to kid cell-phone usage? Well, there're plenty of issues to

consider, and the following tips should be of help.

     Start small.  When thinking about getting your child's first phone, consider having your child first use

your cell phone for occasions when you'll need to know the time and place for pickup,  or in cases of

emergency. If the youngster handles your cell phone appropriately, consider allowing the child to have his

or her own phone with a small amount of voice minutes or text capability (容量) each month. This also

helps teach budgeting.

     Practice together.  Practice voice messaging and text messaging with your child. Both of you need to

become skillful at these techniques, and your child needs to see that you understand how to check his or

her texts, when the phone is being used and also who they're communicating with.

1. In the view of the author, ________.

A. every child should have his or her own cell phone

B. children should not use adults' cell phones

C. adults should be clear about whom their kids contact

D. most adults are not familiar with functions of their cell phones

2. When the author advises parents to start small, he means that parents should ________.

A. set a limit, on the phone bill

B. buy cell phones of small size

C. not use cell phones frequently

D. not teach teens to use cell phones

3. We can learn from the passage that________.

A. it's a waste of money for children to use cell phones

B. cell phones give children lots of benefits

C. it's impossible for people to go without cell phones nowadays

D. most children pay their phone bills by themselves

4. The passage mainly intends to ________.

A. advise buying teen cell phones

B. point out cell phones' advantages

C. help teens choose cell phones

D. offer parents some useful advice

中国哲学没有一个独立的形上学传统，它追求的是对个人道德和社会政治的实践意义，所以又被称为（）。

A.思辨哲学

B.抽象哲学

C.主观唯心哲学

D.道德心性之学或伦理政治哲学

简述农药代谢的途径？