24．Last Monday，while the students on the playground watching the national flag
being raised，something unexpected ．
A. were standing；arose
B. stood；was arising
C. had stood；had arisen
D. would stand；would arise
网友回答
(答案→)A. were standing；arose
B. stood；was arising
C. had stood；had arisen
D. would stand；would arise
解析：可联系答.案.网客服索取。