仪表校准和试验用的标准仪器仪表应具备有效的计量检定合格证明，其基本误差的绝对值不宜超过被校准仪表基本误差绝对值的1／3。
参考答案：对
读短文，补全句子。
It's Saturday today. It's seven in the morning. My mother is doing morning exercises and my father is
cooking breakfast. Grandpa is reading the newspaper. Grandma is watering the flowers. My brother Jack is
still sleeping. I'm writing an e-mail to my new friend, John. We are ready for the weekend.
1. _______________ reading the newspaper.
2. _______________ writing an e-mail.
3. _______________ sleeping.
4. _______________ cooking breakfast.
5. _______________ doing morning exercises.
巨大卵巢囊肿与大量腹水鉴别，以下哪项体征有帮助
A．有振水感
B．平卧叩诊脐部为浊音，双侧为鼓音
C．主要是下腹部膨隆
D．肠鸣音存在
E．听到静脉"营营音"
