（）是指债务人的信用评级在风险期内由当前评级状态转移至其他所有评级状态的概率或可能性

A

"In only six clays I lost seven pounds of weight. "
"Two full inches in the first three days!"
These are the kinds of statements used in magazine, newspaper, radio and television ads. , promising new shapes and new looks to those who buy the medicine or the device. The promoters of products say they can shape the legs, slim the face, smooth wrinkles, or in some other ways to add to beauty or desirability.
Often such products are nothing more than money-making things for their promoters. The results they produce are questionable, and some are dangerous to health.
To understand how these products can be legally promoted to the public, it is necessary to understand something of the laws covering their regulation. If the product is a drug, FDA (Food and Drug Administration)can require proof (证明) under the Food, Drug, and Cosmetic Act that is safe and effective before it is put on the market. But if the product is a device, FDA has no authority to require pre-marketing proof of safety or effectiveness. If a product already on the marker is a danger to health, FDA can request the producer or distributor to remove it from the market voluntarily, or it can take legal action, including seizure (查封) of the product.
One notable case a few years ago involved an electrical device called the Relaxacisor, which had been sold for reducing the waistline. The Relaxacisor produced electrical shocks to the body through contact pads. FDA took legal action against the distributor to stop the sale of the device on the grounds that it was dangerous to health and life.
Obviously, most of the devices on the market have never been the subject of court proceedings (法律诉讼), and new devices appear continually. Before buying, it is up to the consumer to judge the safety or effectiveness of such items.

FDA can ask for the proof of safety and effectiveness of a product ______.

A．if it is a drug

B．if it is a device

C．if its consumers make complaints

D．if its distributors challenge FDA’s authority

贝贝给爷爷奶奶砸核桃，她先给爷爷砸了7个，给奶奶砸了17个，如果她要使奶奶的核桃数是爷爷的3倍，应怎么做？  

某溶液由盐酸、碳酸钠溶液、稀硫酸、氯化铜溶液中的一种或几种混合形成，现向该混合溶液中滴入氢氧化钡溶液，产生沉淀的质量与加入氢氧化钡溶液体积的关系如图所示．则下列关于溶液中溶质的判断正确的是（　　）

A．肯定没有碳酸钠

B．肯定有硫酸

C．是否含有氯化铜不能确定

D．至少含有硫酸或盐酸中的一种，也可能两种同时含有

计划工作必须始终坚持以目标为导向（）

A.系统性原则

B.重点原则

C.创新原则

D.弹性原则

E.可考核性原则

挡土墙泄水孔进口处的反滤层应选用不透水材料。 ( )