当（）时的光照强度称光偿点。
A. 光合作用吸收的二氧化碳与呼吸作用放出的二氧化碳相等
B. 光合作用吸收的二氧化碳大于呼吸作用放出的二氧化碳
C. 光合作用吸收的二氧化碳小于呼吸作用放出的二氧化碳
D. 以上都不对
A user on your network downloads a video card driver from the Internet. You are unsure of the source of the driver. You want to ensure that the user does not lose production time because of an incompatible driver. What should you do?（）
A. Install the driver into the computer. Restart the computer. Use the last known good configuration to recover the original driver if necessary.
B. Install the driver in the computer. Use the hardware troubleshooter and then use the recovery console to recover the original driver if necessary.
C. Display the advanced attributes of the video card driver file. Install the file only if the contents have been secured.
D. Run file signature verification utility to verify that the driver has been digitally signed.&e
烧结机配料量为34kg/m，皮带速度为1.25m/s，求每小时的配料量。
碳家族中，C60的分子结构形似足球。关于C60的说法中，错误的是（）。
A. 它是一种单质
B. 每个C60分子由60个碳原子构成
C. 它与金刚石是同一种物质
D. 它完全燃烧后的产物是CO2
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