_____the activities might seem childish, actually they require a lot of strength and determination.
| A．Since | B．Although | C．Before | D．If |
____ is certain, though, is that the mystery of Tutankhamun’s tomb has never been fully explained.
| A．It | B．What | C．This | D．As |
Some time after the rockets and the space shuttle are _____, the rocket will _____ the space shuttle and ____ the sea.
| A．set sail; broadcast; drop in | B．ruled out; orbit; show up |
| C．stepped up; survive; fall for | D．launched; separate from; fall into |
London people always take umbrellas with them, just _______ it rains.
| A．in case | B．fear | C．so that | D．so long as |
Experts suggest that teenagers spend at least 30 minutes exercising, five times a week. Walking and riding your bike _____ , and ______.
| A．counts; so are school sports | B．count; school sports count, either |
| C．count; so do school sports | D．counts; so school sports do |
As a matter of fact, _____ of sleep can make you look tired, and even _____ putting on weight.
A. lose; cause B lost; result from C loss; result in D losing; lead