一根旗杆在阳光照射下,在地面上投下一个旗杆的影子。自早晨到黄昏这段时间内,旗杆影子长度变化是:[ ]
A.逐渐变短
B.逐渐变长
C.先变长后变短
D.先变短后变长
答案:D
Mary suggested that the problem worth paying attention __________at the meeting. [ ]
A. to be discussed
B. to been discussed
C. being discussed
D. be discussed
我国特有的珍稀植物有_____、_____等。我国特有的珍稀动物有_____、_____、_____、_____ 等。