一物体自距地面H高处自由下落，当速度达到着地速度的一半时，它下落的高度是[ ]

胸部损伤后能导致急性循环衰竭的是下列哪项

A．多根多处肋骨骨折

B．支气管内分泌物增多

C．开放性气胸

D．张力性气胸

E．心包积血

根据句意，用括号内所给单词的适当形式填空。

1. Daniel is ______ (energy) enough to be the host of the charity show.

2. Yesterday Sam celebrated his _______ (twenty) birthday with some of his classmates.

3. Some people do not have enough money for _______ (medicine ) treatment.

4. As we all know China _______ (success) sent up her first man-made satellite in 1970.

5. Some students like to use yellow stationery because it is the color of _______ (wise).

染色平纹机织物制女衬衫(按重量计含亚麻和涤纶短纤各50%)

预防自杀措施？