1 mary had prepareed carefully for her biology eaxmination so that she could be sure of passing it on he fist[ ]1.intention 2.attempt 3.purpose 4.desire 第2道.[ ] ,the conference started.1.having taken their seats 2 haven taken their places

1 mary had prepareed carefully for her biology eaxmination so that she could be sure of passing it on he fist[ ]1.intention 2.attempt 3.purpose 4.desire 第2道.[ ] ,the conference started.1.having taken their seats 2 haven taken their places
1 mary had prepareed carefully for her biology eaxmination so that she could be sure of passing it on he fist[ ]1.intention 2.attempt 3.purpose 4.desire 第2道.[ ] ,the conference started.1.having taken their seats 2 haven taken their places

1 mary had prepareed carefully for her biology eaxmination so that she could be sure of passing it on he fist[ ]1.intention 2.attempt 3.purpose 4.desire 第2道.[ ] ,the conference started.1.having taken their seats 2 haven taken their places
2,玛丽很仔细的准备生物考试,这样才能确保第一次尝试就过.根据意思选2
2,排除法,后面主语是conference,所以前面不能用ing,用ing就表示the conference坐下了

2
1

第一个选attempt 尝试
第二个选having taken their seats，take one's seat是指坐下来,take one's place是代替某人位置