The train starts _____ 6:20，so you’d better get there before 6.
The train starts \_\_\_\__ 6:20，so you’d better get there before 6.
所以
The number of primary schools in the rural areas _____ doubling in the past 50 years.
The number of primary schools in the rural areas \_\_\_\__ doubling in the past 50 years.
Tom and John seldom go to the library in the evening, _____?
Tom and John seldom go to the library in the evening, \_\_\_\__?
From the passage, we leant that _____.
From the passage, we leant that \_\_\_\__.
反应（正反应吸热）在可变容积的密闭容量中进行，下列条件的改变对其反应速率几乎无影响的是（ ）．
反应（正反应吸热）在可变容积的密闭容量中进行，下列条件的改变对其反应速率几乎无影响的是（ ）．
一理想变压器原线圈与副线圈匝数之比为4：1，当它正常工作时，通过原、副线圈的电流之比及输出与输入功率之比分别为（ ）．
一理想变压器原线圈与副线圈匝数之比为4：1，当它正常工作时，通过原、副线圈的电流之比及输出与输入功率之比分别为（ ）．
一定质量的理想气体状态变化P-T图像如图3所示．由图可知下列说法不正确的是（ ）．图3
一定质量的理想气体状态变化P-T图像如图3所示．由图可知下列说法不正确的是（ ）．图3
Florida’s busiest airport will be the first in the country to scan face of all passengers.
Florida’s busiest airport will be the first in the country to scan face of all passengers.
Under no circumstance _____ to tell lies to parents.
Under no circumstance \_\_\_\__ to tell lies to parents.