单项选择题
Precious metals such as gold and silver have been used as money.这句话的中文意思是（）
A. 贵重金属里包括黄金、白银和货币。 B. 诸如黄金和白银等这类贵重金属曾经作为货币使用过。 C. 贵重金属里的黄金、白银都被货币所替代。
判断题 Legal protection on a brand comes into force only after registration.
判断题 The trademark symbols TM and ? can be exchanged in a brand.
判断题 A trademark may be regarded as a protection for a brand name.
