在实验操作时，应根据化学药品特性确定用量，以防事故发生。
A. 对
B. 错
对于机械加工类设备，必须在熟练操作者的指导下学习正确操作方法，严格遵守操作规程，以防在设备运行过程中造成切割、被夹、被卷等意外事故。
A. 对
B. 错
Where is St. Patrick's Day celebrated?
A. In Japan.
B. In America.
C. In India.
D. In Thailand.
Why do people racedragon boats during the Dragon Boat Festival?
A. To commemorate the death of Qu Yuan.
B. To welcome the coming year.
C. To celebrate the harvest.
D. To mark the end of the old year.
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