【单选题】小球重P,置于光滑的圆柱面上,图(a)和图(b)为所画受力图,则( )。A.【图片】与【图片】是一对平衡力系 B.【图片】与P是作用力与反作用力C.【图片】与【图片】是作用力与反作用力 D.【图片】与P是作用力与反作用力【图片】
【多选题】what are the following tense we may use to write about the research objectives in the abstract of a research paper?
【单选题】Modal verbs are sometimes used in the abstract of a review article to:
A.
Illustrate the author’s conclusion
B.
Expose the main idea of the paper
C.
Emphasize on the future trend
【单选题】In the abstract of a review article, there are usually five moves, after the move of indicating the reviewed focus, what might follow closely is the move that describes:
D.
the significance of the review
【多选题】what are the following tense may be used when we write about the research objectives in the abstract of a research paper
【简答题】球重 P ,置于光滑的圆柱面上,图(a)和(b)为所画受力图, 请您:(1)指出所有力的大小关系;(2)各力的施力物是谁?(3)哪一对力是平衡的二力?(4)哪一对力是作用力和反作用力?
【单选题】小球重 P ,置于光滑的圆柱面上,图( a )和图( b )为所画受力图,则( )。