1.There is ______ trouble on the frontier; every few months

1.There is ______ trouble on the frontier; every few months fighting breaks out.
选项:
a、constant
b、 continual
c、 continuous
d、 consistent
2.You can’t imagine ______.
选项:
a、what did we have awful weather
b、 what weather awful we did have
c、 what awful weather we did have
d、 what awful weather we had
3.The ______ of new scientific discoveries to industrial production methods usually makes jobs easier to do.
选项:
a、development
b、 application
c、 expression
d、 explanation
4.By 11 o’clock,he will ____ for four hours.
选项:
a、have been studying
b、study
c、will be studying
d、have studying
5.I have always regretted ____ more when I was young.
选项:
a、having not learnt
b、not to have learnt
c、not to learn
d、not having learnt
6.This map gives no ______ of the height of the mountains.
选项:
a、indications
b、 indicates
c、 point
d、 bottom