对于持有《国际防止油污证书》的船舶,在进行《油类记录簿》记载时应同时使用()文字。
A.船上工作文字
B.船旗国官方文字
C.英文或法文
D.西班牙文
参考答案:B, C
按要求改写句子。
1. Jim is playing basketball now. (改成否定句)
Jim ___________ playing basketball now.
2. There are some books on the desk. (改成一般疑问句)
___________ there ___________ books on the desk?
3. Is Linda watching TV in her room? (作否定回答)
No, ___________ ___________.
4. The students are singing under the tree. (对画线部分提问)
___________ are the students ___________ under the tree?
5. The little girl is talking to her mother. (对画线部分提问)
___________ is the little girl ___________ to?
6. Mary is watching TV now. (用every evening改成一般现在时)
Mary ___________ TV every evening.
试述鱼类原肠胚形成过程中胚环和胚盾的形成。