下列词语中没有错别字的一项是（ ） A．书熟、相形见绌、忍俊不禁 B．宽恕、微不足道

--Could you tell me __________?

-- No. Let’s go and have a look. Maybe someone is hurt, and we can help him.

A．what was happened there

B．when they are doing there

C．what is going on there

D．what they were going on there

下列各组物质，分类正确的是（　　）

A．同素异形体：金刚石、石墨、C₆₀

B．非电解质：H₂、醋酸、蔗糖

C．非极性分子：H₂O、CO₂、P₄

D．同位素：O₃、O₂、¹⁶O

Recently, I flew to Las Vegas to attend a meeting. As we were about to arrive, the pilot announced with apology that there would be a slight (16) before setting down. High desert winds had (17) the airport to close all but one runway. He said that we would be (18) the city for a few minutes waiting to (19) . We were also told to remain in our seats meanwhile with our seat belts fastened (20) there might be a few bumps(颠簸). Well, that few minutes turned into about four-five minutes, including a ride that would make a roller coaster(过山车) (21) by comparison. The movement was so fierce that several passengers felt (22) and had to use airsickness bags. As you might guess, that’ s not a good thing to have happen in a(n) (23) space because it only (24) to increase the discomfort of the situation.

About twenty minutes into the adventure, the entire airplane became very (25) There was now a sense of anxiety and fear that could be (26) noticed. Every passenger simply held on for dear life …except one. A (27) was having a good time！ With each bump of the (28) , he would let out a giggle (咯咯地笑)of delight. As I observed this, I (29) that he didn’t know he was supposed to be afraid and worried about his (30) . He neither thought about the past nor about the future. Those are what we gown--ups have learned from (31) . He was (32) the ride because he had not yet been taught to fear it. Having understood this, I took a deep breath and (33) back into my seat, pretending I was (34) on a roller coaster. I smiled for the rest of the flight. I even (35) to giggle once or twice, much to the chagrin(随恼) of the man sitting next to me holding the airsickness bag.

20（）

A.mistake 

B.delay 

C.change 

D.wind

在实际丈量中，采用满尺丈量的方法，即（）。

A.丈量货物的最大部位

B.丈量货物的最小部位

C.丈量货物的中间部位

在血清中不能检测到的HBV标志物是

A．HBsAg
B．HBeAg
C．HBcAg
D．抗-HBe
E．抗-HBc