The iron-containing pigment in red blood cells that carries oxygen is called

Bacteria that contain ”empty” plasmid, (plasmid without the eukaryotic gene) would grow? in all four types of broth.|only in the broth containing both antibiotics.|in the broth containing tetracycline, but not in the broth containing ampicillin.|in the nutrient broth plus ampicillin, but not in the broth containing tetracycline.

The main social services of the iron and steel industry system are the provision of iron and steel products and the consumption of iron ore A: 正确 B: 错误

1803a8273f88c11.png 的英文名称是______。 A: iron (II) carbonate B: ferrous carbonate C: iron carbonate D: ferric carbonate E: iron (III) carbonate

e. Vitamin C supplements may be combined with iron supplements to increase iron absorption.

According to the passage, how did Bessemer method make the mass production of steel possible A: It directed air at melted iron in a furnace, removing all impurities. B: It slowly heated iron ore then stirred it and heated it again. C: It changed iron ore into iron which was a substitute for steel. D: It could quickly find deposits of iron ore under the ground.

The mass of a single iron atom is 9.3 × 10–23 g. Determine the number if iron atoms in regular cube that measures exactly 10 cm on an edge. The density of iron is 7.86 g/cm3  (   )

In ancient time，there was no iron casting，so the needles were made of ______. A: stone B: tree C: iron D: mental

中国大学MOOC: when a bar of iron attracts other pieces of iron，it ____a magnet，and thus the attraction is called mangnetism.

If iron contains more than ____% C, the alloy is referred to a cast iron（） A: 2.11 B: 0.77 C: 4.3 D: 0