可通过眼-眼或眼-手-眼传播，又可通过性接触传播的病原体是

A．沙眼衣原体鼠亚种

B．沙眼衣原体性病淋巴肉芽肿亚种

C．鹦鹉热衣原体

D．沙眼衣原体沙眼生物亚种

E．肺炎衣原体

The "Karat" marking on jewelry tells you what proportion of gold is mixed with other metals. If 14 parts of gold are mixed with 10 parts of base metal, the combination is called 14-Karat (14K) gold. The higher the Karat rating, the higher the proportion of gold in the object. The lowest Karat gold that can be marketed in the United States is 10-Karat gold. Jewelry does not have to be marked with its Karat quality, but most of it is. If there is a Karat quality mark, next to it must be the U.S. registered trademark of the person or company that will stand behind the mark, as required by the National Gold and Silver Stamping Act.

If the jewelry is marked 14 parts of gold mixed with 10 parts of base metal, it will always bear________ mark.

A．a 14K

B．a 10K

C．an 18K

D．a platinum