设\(z = \int_ { { x^2}}^y { { e^t}\sin t} dt\)，则\({z_{xx}=}\) A: \(2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} + 2{x^2}\cos {x^2}} \right]\) B: \( - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} - 2{x^2}\cos {x^2}} \right]\) C: \( - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} + 2{x^2}\cos {x^2}} \right]\) D: \( - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\cos {x^2} + 2{x^2}\sin {x^2}} \right]\)

The firemen have put out a forest fire. The firemen did that at last. The fire was big. The fire broke out in California. A: Finally the firemen have put out a big forest fire in California. B: At last the firemen put out a big forest fire in California. C: At last the firemen have put out a big forest fire in California. D: The firemen have put out a big forest fire in California at least.

Whichone is the efficacy ofwarm nature medicinal A: clear heat B: warm the center and dissipate cold C: drain fire D: cool blood E: resolve toxins

If the fire is in the cargo hold, we should first extinguish the fire. A: 正确 B: 错误

设\(A\)为\(n\)阶方阵,\(\left| A \right| = 2 \)，则\(\left| {\left| A \right|{A^T}} \right|=\) A: \({2^{n + 1}} \) B: \({2^{n }}\) C: \({2^{n - 1}}\) D: \(2\)