内燃机的一个工作循环有四个冲程，其中将内能转化为机械能的是（） A．吸气冲程 B

唐肃宗至德元年（756年）“敕谏议大夫论事，自今后不须令宰相先知。”乾元二年（759年）又规定“两省谏官十日一上封事。”这些规定体现了(　　)

A．谏官主要职能是监督宰相

B．谏官谏议权不断增强

C．谏官隶属尚书、门下两省

D．谏官地位相当于宰相

面对毒品我们不应有的态度是 [ ]

A．坚决拒绝，决不沾染

B．举报你身边有吸毒行为的人

C．有新鲜感，好奇地试一试

D．积极参加反吸毒的宣传活动

Everyone becomes a little more forgetful as they get older, but men’s minds decline more than women’s, according to the results of a worldwide survey.

Certain differences seem to be inherent in male and female brains: Men are better at maintaining and dealing with mental images (useful in mathematical reasoning and spatial skills), while women tend to excel (擅长) at recalling information from their brain’s files ( helpful with language skills and remembering the locations of objects).

Many studies have looked for a connection between sex and the amount of mental decline (衰退) people experience as they age, but the results have been mixed.

Some studies found more age-related decline in men than in women, while others saw the opposite or even no relationship at all between sex and mental decline. Those results could be improper because the studies involved older people, and women live longer than men: The men tested are the survivors, "so they’re the ones that may not have shown such cognitive decline," said study team leader Elizabeth of the University of Warwick in England.

People surveyed completed four tasks that tested sex-related cognitive skills : matching an object to its rotated form, matching lines shown from the same angle, typing as many words in a particular category (范畴) as possible in the given time, e.g. "object usually colored gray", and recalling the location of objects in a line drawing. The first two were tasks at which men usually excel; the latter were typically dominated by women.

Within each age group studied, men and women performed better in their separate categories on average. And though performance declined with age for both genders, women showed obviously less decline than men overall.

One important factor that affects the correctness of the results is that （）.

A．the old men tested may not have shown such cognitive decline

B．people surveyed are all old

C．people taking part in this test came from all over the world

D．women live longer than men

receptor down-regulation (受体减量调节)

“兼爱”“非攻”思想的提出者是（）。