某项目制定的开发计划中定义了三个任务，其中任务A首先开始，且需要3周完成，任务B必须
题型：单项选择题
问题：
某项目制定的开发计划中定义了三个任务，其中任务A首先开始，且需要3周完成，任务B必须在任务A启动1周后开始，且需要2周完成，任务C必须在任务A完成后才能开始，且需要2周完成。该项目的进度安排可用下面的甘特图（）来描述。
A.图A
B.图B
C.图C
D.图D
题型：单项选择题
Light and shadow (影子) are friends. They usually go together. We receive light every day. __________小题1:________________
Light cannot shine through you. ___________小题2:________________ There is a spot(斑点) on the ground next to you. The light cannot reach the dark spot. This is your shadow.
______________小题3:_____________Your body stops very little light from reaching the ground. So your shadow is quite short.
But in early morning or late afternoon the sun is low in the sky. The light moves over more of your body. ___________小题4:_________________ Your body keeps a lot of light from reaching the ground.
We love light, especially sunli
ght. _____________小题5:______________Most of us like to stand in the shadow of a tree in summer. But some people are afraid of their own shadow at night. They do not want to walk in a dark street. They do not want to see the shadow, either. But still light and shadow usually go together. 