与初始T细胞相比，记忆性T细胞再活化时（）。A.更易被激活，相对较低浓度的抗原即可

结构的最后弯矩图为()。

A．图(2)

B．图(3)

C．图(4)

D．都不对

It's a fine day. What about ______? [ ]

A. to go our for a walk

B. going out for a walk

C. going out for a walking

D. go to out for walking

下列哪项不是眩晕肝阳上亢证的主症（）

A.头痛

B.面赤

C.烦躁

D.口苦

E.呕吐

An analyst does research about price-to-earnings ratio and gathered the following nformation about three common stocks with the same retention ratio:

The highest price-to-earnings (P/E) ratio is most likely associated with:()

A. Stock A.

B. Stock B.

C. Stock C.

安全防范主要包括人防、物防、（）。

A、报警器

B、技防

C、巡逻队

D、检查