瓦斯（指甲烷）是一种无色、无味、有臭的气体。
参考答案：错
中国鼻内测验中智力缺陷可分为（ ）
A．1
B．3
C．2
D．4
His parents died when he was five, so he was _____ by his uncle.
A．brought on
B．brought up
C．brought down
D．brought in
