处理TONE及语音发送、DTMF收发号、MFC收发号、忙音检测、会议电话等的什么单板

甲超市向乙电器厂洽谈购买一批电暖器，双方已达成书面协议，尚未盖章。随后乙电器厂按照约定向甲超市发货，甲超市收到货物后即摆放在柜台上销售。一个月后，因销售不理想甲超市要求退货，为此形成纠纷。此案应认定为( )。

A．合同因未盖章尚不成立
B．合同因未盖章无效
C．合同因有书面协议所以成立，但未盖章合同关系无效
D．合同因乙电器厂已经履行供货义务，甲超市接受供货，该合同成立

刺激停止作用于感受器后，感觉现象并不立即消失而保留片刻的现象是( )

A．闪光融合

B．视觉对比

C．后像

D．联觉

Researchers have known that secondhand smoke can be just as dangerous for nonsmokers as smoking is for smokers, but now there’s fresh evidence quantifying just how hazardous the after-burn from cigarettes can be, and how quickly it affects your body. Scientists at the Oregon Department of Health documented for the first time an hourly buildup of a cancer-causing compound from cigarette smoke in the blood of nonsmokers working in bars and restaurants in the state.

Reporting in the American Journal of Public Health, the researchers found that waiters and bartenders working a typical night shift gradually accumulated higher levels of NNK, a carcinogen in cigarette smoke, at the rate of 6 % each hour they worked. NNK is known to be involved in inducing lung cancer in both lab rats and smokers.

"We were somewhat surprised by the immediacy of the effect and the fact that we could measure the average hourly increase," says Michael Stark, the lead author of the study and a principal investigator at the Mulmomah County Health Department in Oregon.

The authors are confident that the increases in NNK in the workers they tested most likely came from their exposure to smoke -- the study included a control group of similar subjects in restaurants where no smoking was allowed. "There is experimental evidence from studies where you put nonsmokers in a room, blow smoke into the room and measure their artery function, that you see the platelets get sticky, which can cause clots and lead to a heart attack, and the ability of the arteries to dilate decreases very rapidly," says Dr. Matthew McKenna, director of the office on smoking and public health for the Centers for Disease Control.

All of which could mean more time loitering outside buildings and in alleyways for smokers intent on grabbing a puff. Thirteen states now prohibit smoking in restaurants altogether (most of these include bars as well), and while 11 states still put no restrictions on lighting up, individual cities within those states -- such as Austin in Texas, for example -- have passed legislation banning smoking in eating establishments and other public areas.

It’s just getting harder to refute the scientific evidence; in a study done in Scotland several months after that nation instituted a ban on smoking in public places, researchers found that following the ban, bar patrons showed per lung capacity and reduced levels of inflammation (a red flag for a number of chronic diseases, including heart disease and asthma). "We made it pretty clear that the science on this is pretty irrefutable," says McKenna. And if smokers have fewer places to smoke, that message may finally get heard.

As is used in Paragraph 4, the phrase "a control group" refers to （）.

A．people working at the Oregon Department of Health

B．people investigating at the Mulmomah County Health Department in Oregon

C．people serving as a standard of comparison for checking test results

D．people involved in passing legislation banning smoking in eating establishments

减慢舒张期时心血管生理上有什么变化（）

A.左心室血液缓慢充盈到主动脉

B.心房缓慢被充盈

C.心房血液缓慢而最后全部充盈到左心室

D.心房血液快速充盈到左心室

E.左心房血液在舒张时相的中期缓慢充盈到左心室

在射能量数值相同的情况下，内照射危害最大的是（）。

A.α射线照射

B.β射线照射

C.γ射线照射

D.β、γ射线混合照射

E.特征X射线照射