但丁创作的《神曲》分为《地狱》《天堂》和（）3部。A.《越狱》 B.《炼狱》 C.《

选出正确的词，并写在横线上。

1. —Have you ever been to Europe?    —No, but I ______ (have been/went) to Africa last year.

2. —Have you ever been to my house?   —No. But I'm coming to your party ______ (tonight/this night).

3. Has Victor ______ (been ever/ever been) to China?

4. In future, people will ______ (spend/waste) a long vacation every year.

5. He is an ______ (exchanged/exchange) student in this school.

连接输送带时，不得站在输送机架子上牵引输送带。

有关细菌营养的说法哪项是错误的( )

A．细菌分为两大营养类型

B．自营菌所需能源是来自无机物的氧化或光合作用

C．异养菌能利用简单的无机物为原料

D．所有病原菌都是异养菌

E．异养菌包括腐生菌和寄生菌两大类

台车通常有哪几种结构形式？