语法有无错?Up to the present,the scientists have been c
1 These scientists have made great c------ to sending up the
up to present?还是up to the present?
Many scientists have ____(aready,yet)been to the North Pole.
Scientists have come up with lots of ideas to explain the en
Scientists throughout the world have been dreaming _____ whe
The phone is ringing,but no one answer the phone.语法有无错啊?
What have you been up to for the past few days?up to
Scientists have many theories about how the universe first c
The scientists believe ( )they have devoten themselves to (
With the population explosion,scientists will have to ____ n
With the population explosion, scientists will have to _____
we have been used to getting up early in order to catch the