肾下垂多发生于（）
A、老年女性。
B、老年男性。
C、青壮年男性。
D、青壮年女性。
E、儿童期。
参考答案：A
— What's the matter, John? You look sad.
— Oh, nothing much. As a matter of fact, I ___ of my friends back home. [ ]
A. just thought
B. have just thought
C. was just thinking
D. have just been thinking
开车过程中，影响常压塔开侧线的关键是（）。
A、是否给塔底吹汽
B、侧线泵是否上量
C、中段回流泵是否上量
D、常压炉出口温度
g much. As a matter of fact, I ___ of my friends back home. [ ]
ng