问题 选择题

X、Y、Z、W、R是5种短周期元素,其原子序数依次增大。X是周期表中原子半径最小的元素,Y原子最外层电子数是次外层电子数的3倍,Z、W、R处于同一周期,R与Y处于同一族,Z、W原子的核外电子数之和与Y、R原子的核外电子数之和相等。下列说法正确的是 [ ]

A.元素Y、Z、W具有相同电子层结构的离子,其半径依次增大

B.元素X不能与元素Y形成化合物X2Y2

C.元素Y、R分别与元素X形成的化合物的热稳定性:XmY>XmR

D.元素W、R的最高价氧化物的水化物都是强酸

答案

答案:C

多项选择题
阅读理解

阅读理解

     When the lazy days of summer arrive and the schedule is packed with swimming, camp, and family

vacations, it can be a challenge to find time for learning. But kids' reading skills don't have to grow cold

once school's out. Here are some ways to make reading a natural part of their summer fun:

     Explore your library. Visit your local library to check out books and magazines that your kids haven't

seen before. Many libraries have summer reading programs, book clubs, and reading contests for even

the youngest borrowers. With a new library card, a child will feel extra grownup checking out books.

     Read on the road. Going on a long car trip? Make sure the back seat is stocked with favorite reads.

When you're not at the wheel, read the books aloud. Get some audiobooks (many libraries have large

selections) and listen to them together during driving time.

     Make your own books. Pick one of your family's favorite parts of summer-whether it's baseball, ice

cream, or the pool-and have your child draw pictures of it or cut out pictures from magazines. Stick the

pictures onto paper to make a booklet and write text for it. When you're done, read the book together.

Reread it whenever you like!

     Keep in touch. Kids don't have to go away to write about summer vacation. Even if your family stays

home, they can send postcards to tell friends and relatives about their adventures. Ask a relative to be

your child's pen pal and encourage them to write each week.

     Keep up the reading habits. Even if everything else changes during the summer, keep up the reading

routines around your house. Read with your kids every day-whether it's just before bedtime or under a

shady tree on a lazy afternoon. And don't forget to take a book to the beach!Just_brush_the_sand_off_

the_pages-it's_no_sweat!

1. The purpose of the passage is to________.

A. encourage parents to read

B. give advice on raising kids

C. raise a good summer reader

D. suggest places for vacations

2. If you drive on a long trip in summer, you can________.

A. visit the local library and join book clubs

B. borrow some audiobooks to listen to

C. keep in touch with friends by sending postcards

D. read your own picture books with your son

3. By saying "Just brush the sand off the pages-it's no sweat", the author means________.

A. taking away the sand on the book is very difficult

B. a special book is needed when you're reading on the beach

C. one can remove the sand on the book with a brush easily

D. there's no trouble reading even on the beach

4. Who are the intended readers of the passage?

A. Parents.  

B. Students.

C. Teachers.  

D. Editors.