—Have you thought of the topic for the composition?

— Not yet．I _____ it very carefully, but I haven’t decided．

A．will consider

B．have been considering

C．had considered

D．was considering

下列哪一项不是热拌沥青混合料马歇尔试验技术指标.（）

A.击实次数

B.稳定度

C.残留稳定度

D.抗车辙能力