在一般情况下，收缩压的高低主要反映下述哪一项的变化A．心率 B．外周阻力 C．循环血

What does the speaker mean a. It is not very possible that this news may change the mind of David. b. It is not very possible that this news may cause much attention of David. c. It is not very possible that this news may be welcomed by David. d. It is not very possible that this news may do any good to David.

农信银支付清算系统的服务对象是全国农村合作金融机构，包括哪些机构及所属的营业网点。（）

A.农村信用社

B.农村信用联社

C.农村商业银行

D.农村合作银行

—Why are you so excited?

—Lucy invited me ______ to her birthday party.

A．to go

B．go

C．going

D．went

白细胞有细胞核，成熟的红细胞和血小板没有细胞核．______（判断对错）

按浮充电运行方式工作的蓄电池组，正常直流负荷是由（）提供的。