销售商品时，与“主营业务收入”相对应的账户可能有（）A、银行存款B、应收账款C、预收账款D、现金

Taking more exercise will prevent you _______weight.

A. to put up

B. putting up

C. to put on

D. putting on

The middle-aged lady surrounded by the mass is said_______.

A. to be main

B. being main

C. to be chief

D. being chief

Having entered the hall, she found a chair in one corner and _______herself silently.

A. sitting

B. sat

C. seating

D. seated

_______more attention, the young trees could have grown much better.

A. To give

B. Given

C. Give

D. Having given

Now, she is upstairs _______a long speech for the president.

A. preparing

B. was preparing

C. prepared

D. to prepare

The teacher came into the room, with his hands _______behind his back.

A. being crossed

B. having crossed

C. crossed

D. to be crossed

you're burning the mid-night oil in sympathy. In the race to improve educational standards, (22) are throwing the books at kids. (23) elementary school students are complaining of homework fatigue. What's a well-meaning parent to do?

As hard as (24) may be, sit back and chill experts advise. Though you've got to get them to do it, (25) helping too much, or even examining answers too carefully, you may keep them (26) doing it by themselves. "! wouldn't advise a parent to check every 27 assignment," says psychologist John Rosemond, author of Ending the Tough Homework, "There's a (28) of appreciation for trial and error. Let your children (29) the grade they deserve."

Many experts believe parents should gently look over the work of younger children and ask them to rethink their (30) . But "you don't want them to feel it has to be (31) ," she says.

That's not to say parents should (32) homework—first, they should monitor how much homework their kids have. Thirty minutes a day in the early elementary years and an hour in (33) four, five, and six is standard, says Rosemond. For junior-high students it should be" (34) more than a hour and a half," and two for high school students. If your child consistently has more homework than this, you may want to check (35) other parents and then talk to the teacher about reducing assignments.

21.

A. very

B. exact

C. right

D. usual

A. officials

B. parents

C. experts

D. schools

A. Also

B. Even

C. Then

D. However

A. there

B. we

C. they

D. it