查询词典 keep from doing

We cannot always have associative law for operations, for instance, we did not have this law for mixed addition and multiplication,neither for subtraction, 2+3 2+1≠(2+3)(2+1)=5 3,（2-3）- 2≠2-（3-2）,this is why we have to set the rule in operations that "doing inside bracket at first and out side afterwards, doing multiplication and dividing first and addition and subtraction afterwards".

注意运算的结合律并不是永远对的，比如加法和乘法的混合运算就没有结合律，减法也没有，2+3 2+1≠5 3，（2-3）- 2≠2-（3-2），因此我们运算中总是规定先括号内再括号外，先加减后乘除。

Be used to sth./doing sth.= be accustomed to sth./doing sth.

意为"习惯于做某事"；可用于现在、过去、将来等多种时态。

Be busy doing sth She is busy doing her homework now.

她现在忙于做家庭作业。

Be busy with/doing sth = be up to sth = be occupied with I think you were busy with/doing your homework.

我以为你当时在忙着写作业。

Be good at sth ./ doing sth.= do well in sth ./ doing sth .

意思是"擅长做某事"或"在某方面做的好"。

Be good at doing sth.= do well in doing sth.

擅长做某事，在……方面做得好。

I'm just doing what I'm supposed to be doing.

我只是做了我应该做的，我

Worth be worth some money /be well worth sth./doing sthWorthwhile it's worthwhile to do sth./doing sth.

许多国家目前正处于法律困境，因为他们一直没有保护知识产权的法律，知道最近才通过了有关法律。

Be worth doing 值得 I think it is worth doing all this, though.

然而，我认为这一切都值得做。

It 's worthwhile doing be worth doing sth.

这问题不值得反复讨论。

There are different types of personal loans available.

有许多不同类型的个人贷款优惠。

The above mentioned teaching model of spiral rising can be used to avoid rigidness in teaching.

上述螺旋式上升的教学模式，可以避免教学形成模式後的僵化现象。