A:unle
B:in case
C:as far a
D:as long a
— If we are quick enough, we can ________before nine o'clock.
— We don't need to ________the park so early.
关于右图所示实验装置的叙述错误的是( )
当曲线y=4-x2与直线kx-y-2k+3=0有两个相异的交点时,实数k的取值范围是 ( )