在进行原码乘法时，乘积的符号位是由被乘数的符号位和乘数的符号位通过______运算来

根据句意及首字母提示在横线处填上恰当的单词，使句子意思完整，语法正确。

1. The desserts are very delicious. Have you t_______ them?

2. The price of the car is i_______ so fast that I can't afford it.

3. He is a v_______, so he eats mainly vegetables.

4. —How well Mary sings!    

    —Yes.  She has a s_______ voice.

5. Be careful when you cross the m_______ road because there are many people and cars on it.

6. Lei Feng,  a great soldier,  will live in everyone's h_______ forever.

7. You can't e_______ to learn a foreign language in two months.  That's impossible.

以下哪种头痛可表现为空痛的特点

A．脾虚头痛

B．风湿头痛

C．肾虚头痛

D．气虚头痛

E．血虚头痛

气瘿，肉瘿等按之坚实或有囊性感，不红不热，其证多属（）

A.痰火郁结

B.冲任失调

C.肝郁气滞

D.气虚血瘀

E.痰凝

避孕针1号为

A．戊酸雌二醇和氯地孕酮
B．炔雌醇和炔诺酮
C．炔雌醇和18-甲基炔诺酮
D．炔雌醇和氯地孕酮
E．18-甲基炔诺酮

精密度是用偏差值来量度，分为（）精密度和（）精密度。