对于矩阵\[ A = \left[ {\begin{array}{*20{c}} 1&2\\ 0&1 \end{array}} \right] 与矩阵 B = \left[ {\begin{array}{*20{c}} 1&2\\ 2&1 \end{array}} \right], \]则` A `与` B `（ ） </p></p>
对于矩阵\[ A = \left[ {\begin{array}{*20{c}} 1&2\\ 0&1 \end{array}} \right] 与矩阵 B = \left[ {\begin{array}{*20{c}} 1&2\\ 2&1 \end{array}} \right], \]则` A `与` B `（ ） </p></p>
to begin or cause something to begin: ______
to begin or cause something to begin: ______
________, you must continue. A: Once you begin B: When you begin C: Once you will begin D: While you begin
________, you must continue. A: Once you begin B: When you begin C: Once you will begin D: While you begin
How to begin a topic? We can begin with __________.
How to begin a topic? We can begin with __________.
When will the sale begin The sale will begin from ______.
When will the sale begin The sale will begin from ______.
According to the research, 20% of the population was ___________of developing lung disease from second-hand smoking. ( ) A: at a time B: to begin with C: at hand D: at risk
According to the research, 20% of the population was ___________of developing lung disease from second-hand smoking. ( ) A: at a time B: to begin with C: at hand D: at risk
PL/SQL块由（ ）组成 A: DECLARE BEGIN END B: BEGIN END C: EXCEPTION BEGIN END D: DECLARE BEGIN EXCEPTION END
PL/SQL块由（ ）组成 A: DECLARE BEGIN END B: BEGIN END C: EXCEPTION BEGIN END D: DECLARE BEGIN EXCEPTION END
\[A = \left[ {\begin{array}{*{20}{c}} 2&2&3\\ 2&3&1\\ 3&4&4 \end{array}} \right]\]，且`\BA = A + B`，则矩阵`\B=` （ ） </p></p>
\[A = \left[ {\begin{array}{*{20}{c}} 2&2&3\\ 2&3&1\\ 3&4&4 \end{array}} \right]\]，且`\BA = A + B`，则矩阵`\B=` （ ） </p></p>
汇编语言中的“end begin”中的begin指的是______。
汇编语言中的“end begin”中的begin指的是______。
It is necessary that the meeting ____ at once. A: began B: begin C: begins D: will begin
It is necessary that the meeting ____ at once. A: began B: begin C: begins D: will begin