供人类呼吸的气体是（ ）
A．氧气
B．氮气
C．二氧化碳
D．稀有气体
答案：A
题目分析：供人类呼吸的气体是氧气，答案选择A
用所给词的适当形式填空，使句子意思完整通顺。
1. Some _____(Italy) will visit their university next week.
2. Jenny is one of the most _____(success) students in her class.
3. Linda’s_______(perform) at the party was well received.
4. The old doctor uses sport as part of his patients’ _____(treat).
5. Frank was the first to run across the ______(finish) line at the sports meeting.
用酶联免疫吸附试验(ELISA)最早检出SARS冠状病毒抗体的时间为
A．1dB．7dC．10dD．15dE．28d
