The atomic weight of oxygen is_____than ______of the hydrogen.
| A．15 times heavier; that |
| B．15 times heavier: those |
| C．16 times as heavier; that |
| D．16 times as heavy; those |
Though ______ to see us，the professor gave us a warm welcome。
A. surprise B was surprised C. surprised D. being surprised
—Have you finished the book？
-- No. I’ve read up to _____ the children discover the secret cave.
| A． which | B． what | C． that | D．where |
Barbara is easy to recognize as she’s the only of the women who ____ evening dress.
| A． wear | B． wears | C． has worm | D． have worm |
My mother opened the drawer to _________ the knives and spoons.
| A． put away | B． put up | C． put on | D．put togeth er |
T
om was about to close the windows _____his attention was caught by a bird.
| A．when | B．if | C．and | D．till |