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[单选题]

规格8.480.1852923604R的内螺纹芯头，29代表什么含义：（)

A.芯头齿顶角29°

B.芯头螺旋角29°

C.生产铜管齿顶角29°

D.生产铜管螺旋角29°

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更多“ 规格8.48*0.185*29*23*60*4*R的内螺纹…”相关的问题

第1题

规格8.48*0.185*29*23*60*4*R的内螺纹芯头，8.48代表什么含义：（)

A.芯头实际外径8.48mm

B.芯头名义外径8.48mm

C.管坯内径8.48mm

D.铜管外径8.48mm

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第2题

规格8.48*0.185*29*23*60*4*R的内螺纹芯头，60代表什么含义：（)

A.芯头齿顶角60°

B.齿条数60条

C.芯头长60mm

D.芯头倒角60°

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第3题

正常成人体内，蛋白质所占的比例是（）。

A.6%～90%

B.16%～19%

C.23%～29%

D.36%～39%

E.46%～49%

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第4题

1 1/2 6/11 17/29 23/38 ()

A.117/191

B. 122/199

C. 28/45

D. 31/47

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第5题

1，1/2 ， 6/11 ，17/29 ， 23/38 ，（）

A.28/45

B.117/191

C.31/47

D.122/199

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第6题

听力原文：When Rome emerged as a world power, the difficulties of making a calendar were we

ll known, but the Romans complicated their lives because of their superstition that even numbers were unlucky. Hence their months were 29 or 31 days long, with the exception of February, which had 28 days. However, four months of 31 days, seven months of 29 days, and one month of 28 days added up to only 355 days. Therefore the Romans invented an extra month called Mercedonius of 22 or 23 days. It was added every second year.

One year, made 445 days long by imperial decree, brought the calendar back in step with the seasons. Then the solar year (with the value of 365 days and 6 hours) was made the basis of the calendar. The months were 30 or 31 days in length, and to take care of the 6 hours, every fourth year was made a 366-day year. Moreover, Caesar decreed the year began with the first of January, not with the vernal equinox in late March.

This calendar was named the Julian calendar, after Julius Caesar, and it continues to be the calendar of the Eastern Orthodox churches to this day.

(30)

A．Shortage of days.

B．Superstition.

C．Inability to divide the year.

D．Too many months.

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第7题

23 29 31 37 ()

A.41

B. 40

C.43