单词填空。

1. Can I buy lunch for you ______ (作为报答) for your help?

2. This vase is valued ______ (少于) 40 dollars.

3. Those two countries have been _______ (交战) for a long time.

4. The machine has already been _______ (拆开).

5. John mentioned several judges' names, but he didn't ______ (评价高) them.

6. There is no d______ that he will get the first prize.

7. Pandas are a kind of r______ animals.

人体白细胞能吞噬入侵的细菌、细胞碎片或衰老的红细胞，在白细胞中与这些物质消化有密切关系的细胞器为[ ]

A．溶酶体

B．核糖体

C．液泡

D．中心体