农业综合开发土地治理项目分四个阶段:前期准备阶段、申报批复阶段、项目实施阶段、()。
参考答案:验收管护阶段
如图所示,平行直线表示电场线,但未标方向,带电为+10-2C的微粒在电场中只受电场力作用,由A点移到B点,动能损失0.1J,若A点的电势为-10V,则
①B点的电势为10V
②电场线方向从右向左
③微粒的运动轨迹可能是轨迹1
④微粒的运动轨迹可能是轨迹2
以上正确的是
A.①③
B.②④
C.②③
D.①④
Depths in the routes (Malacca and Singapore Straits) vary between 20m and about 23m but there are many areas of sand waves and depths are liable to change. The statement infers that().
A.depths in Malacca and Singapore Straits are stable
B.depths in Malacca and Singapore Straits are changeable
C.depths in Malacca and Singapore Straits are invariable
D.depths in Malacca and Singapore Straits are the same all the time