问题 多项选择题

植物通过双受精形成的种子,哪些组织是二倍体?()

A、胚

B、胚乳

C、果皮

D、种皮

答案

参考答案:A, C, D

阅读理解

阅读理解

     Vans, Keds, Dollies-they sound like the names of rock bands, but if you have teenagers, you'll know

they're actually the latest in teenage footwear.

     But experts are now warning that the current shoe fashions will be causing teenagers discomfort in the

short term and storing up years of foot, knee and back pain in the future.

Here, the experts identify the problems caused by teenagers'shoe choice.

KEDS/VANS

     Slipon shoes with elastic (弹性的) sides are particularly popular among teenage boys-with Keds and

Vans the most soughtafter brands.

     The main problem is that they are just too flat-so flat that the heel, which strikes the ground first,

becomes damaged and painful.

BALLET PUMPS

     The worst shoes of all are such light and thin dolly shoes.The problem is partly their flatness, as with

Keds and Vans.However ballet pumps, which  have no string or heel, have other specific problems.

     "As the shoe has no fastening device, it relies on the toes to keep the shoe on, causing an awkward

gait (步法), this leads to shortand longterm problems such as calluses (茧子), heel and knee pain."

WEDGES AND STILETIOS

     These shoes can also cause problems with gait.They may look good, but the heels on these are so high they can force the wearer's body weight forward, making them very unstable.

     Teens who wear these shoes regularly are also in danger of joining those millions of women with

constant back pain.

SCHOOL SHOES

     So what do podiatrists (足科医生) have on their wish list, especially for everyday wear?

     Something in a natural, breathable fabric, with a string to hold it on, with a small heel and a deep toebox that does not press the toes, such as Clark's, Marks & Spencer or Rhino.

     If your teen insists on wearing 'bad'shoes, get them some simple foot orthotics (矫形器) in the shoes.

These support and correct the movement of the foot and, properly fitted by a podiatrist, can often

transform their walk and halt the damage.

1. Of all the shoes mentioned in the passage, which can cause the worst problems?

A. Marks & Spencer.  

B. Wedges & Stilettos.

C. Keds and Vans.  

D. Ballet Pumps.

2. Which pair of shoes may not be found on the podiatrists'wish list?

3. The underlined word "halt" in the last paragraph probably means________.

A. increase  

B. worsen  

C. stop  

D. cure

4. From this passage we can infer________.

A. trendy shoes may ruin teenagers' health

B. fashionable shoes all have orthotics in them

C. experts are strongly against wearing popular shoes

D. podiatrists are experts at producing branded shoes

5. In which column of Mail Online can you find this passage?

A. Sports.  

B. Science.  

C. Health.  

D. Shopping.

单项选择题