未知题型 The phrase 'put on their thinking caps' (Line 5, Paragraph 2) most probably meansA.try to solve problems.B.risk their proposals.C.strive to delay the events.D.deserve economic and military musclE.

问答题 水的气-液饱和状态是指[填空1]速度=[填空2]速度。

未知题型 The term 'fisticuffs' (Paragraph 2) probably meansD.irony