48与15的积减去644除以4的商，差是多少？

Because of ill health, she has been obliged to _____ her job. [ ]

A. resign

B. depart

C. retire

D. dismiss

用括号中所给词的适当形式完成句子。

1.  She always eats thin meat ____(keep) thin.

2.____   (communicate) is very important between lovers.

3. Now the students in China get         (much) exercise than years ago.

4. The father often keeps him____ (take) different lessons.

5. Work____(hard) and you'll do better in your studies.

以下程序输出结果为______。
#include＜iostream＞
using namespace std;
class TestClass 1

public:
TestClass1()
TestClass1(int i)
x1=i;
void dispa()
cout＜＜"x1="＜＜x1＜＜",";
private:
int x1;
:
class TestClass2:public TestClass1

public:
TestClass2()
TestClass2(int i):TestClass1(i+10)

x2=i:

void dispb()

dispa();
cout＜＜"x2="＜＜x2＜＜end1;

private:
int x2:
:
int main()

TestClass2 b(2):
b.dispb();
return 0;

泡沫灭火器用于扑救（）等引起的火灾。

A、汽油

B、电器

C、柴油

D、木材

E、酒精

用于气胸时抽气在（）

A.胸骨中线第2肋间，患者取仰卧位

B.胸骨中线第2肋间，患者取坐位

C.肩胛下第7肋间或第8肋间

D.腋中线第5肋间或第6肋间处

E.腋前线第5肋间或第6肋间处